Multiple pregnancy: a period of special situation. The probability of multiple pregnancy What is the risk of multiple pregnancy

Today, the number of multiple pregnancy compared with the last century has increased significantly. This is due to the fact that the number of inductions has increased, and the age of women who give birth to children has increased. However, along with this, with the percentage of such pregnancies, the risks associated with the development of 2 or 3 or more children at the same time and their birth also increase.

Multiple pregnancy is a pregnancy with an increased risk of various complications, therefore, such women are monitored more carefully than those who bear one child under the heart. Let's take a closer look at all the nuances.

Peculiarities

The number of such pregnancies is approximately 60-70%, and the kids have an outward resemblance to each other, like ordinary sisters or brothers. It could be a boy or a girl in different colors hair, with a cut and eye color, with different characters. These babies are called fraternal twins.

In this case, each fetus has its own placenta. Every child has amniotic sac. They develop separately.

If a woman is carrying 3 or more children, then dizygotic and monozygotic pregnancies may be present at the same time.

Monozygotic twins

Depending on the number of children, monozygotic twins and triplets are distinguished. In this case, the kids develop from one cell. At a certain time, it divides into 2 or more embryos. Children all subsequent time will develop the same, but according to different programs.

In this case, we are talking about twins or monozygotic twins. The external similarities of such children are one hundred percent, they have the same everything - the shape of the teeth, the voice of the hair blows, and so on.

Features of the development of multizygous twins

Identical twins develop in the early stages of zygote division. This is the determining factor in the development of such children. So if:

• The zygote divided during the first 2-3 days after fertilization, then 2 independent chorions and 2 amnions are formed in children. Simply put, every child has a fetal bladder, a placenta. In some cases, the placentas of two children can fuse together.
• If the division occurred in the interval from 4 to 8 days after fertilization, then the children will develop in one placenta, united by one membrane. However, each child has a personal amniotic sac.

If the division occurs from 9 to 13 days, then one placenta and membranes are formed, most often in this case, Siamese twins are born.

It is possible to determine whether twins belong to a certain type after childbirth. If there are partitions of 2 membranes between the children, then these children are identical, if the placentas are different and there are 4 partitions, then these are heterozygous children.

To date, this can also be established using ultrasound diagnostics, starting from the 4th month of gestation. This is necessary in order to choose a pregnancy management plan. If a woman is pregnant with two (or more) children at the same time, then you need to carefully monitor how the children develop, because there may be various violations in their development.

Flow

Initially, for a woman, such a pregnancy is quite problematic, it is classified as a deviation from the norm. This condition should be monitored regularly and carefully.

From the first 3 months of gestation, various disorders may occur, deterioration of well-being. The task of the treating doctor who manages the pregnancy is to familiarize the expectant mother with potential deviations and disorders so that she is aware of how to behave and when to go to the hospital.

Doctors say that multiple pregnancy is a complex process. Maximum complications are possible when a woman is pregnant with twins who have different Rh factors and blood groups.

Problems in the early stages of gestation

At the initial stages of gestation, the condition does not have any special differences, however, bleeding may develop on days 7-8.

It can last about 3-4 days. In some cases, such bleeding opens very strongly and spontaneous abortion begins - a miscarriage. It should also be noted that with such a pregnancy, pregnancy symptoms and toxicosis are more pronounced.

Problems in the middle of the term

With multiple pregnancy, ICI often develops in the middle of the term. In this condition, the uterine cervix becomes very weak, it becomes problematic for it to withstand the weight of the children. This condition develops due to the fact that the uterine walls are actively stretched, an increased amount of amniotic fluid is observed, the fruits weigh more.

Such a pathology usually occurs after 21-22 weeks of gestation, occurs quite quickly, and progresses just as quickly. If with multiple pregnancy, when it comes to two children, you can still suture the neck, then with triplets or more, this will not help, since the load is very large.

Problems in the later stages of gestation

As children develop and their weight increases, the volume of circulating blood increases. This causes high stress on the heart muscle. The blood is “diluted”, which causes the development of anemia and an increased need for mineral components and vitamins.

Often a woman experiences severe heartburn, gets tired very quickly, she has stool disorders, and urination is also disturbed. This is due to the fact that the uterus begins to actively increase in size, and puts pressure on the intestines, ureters and other organs.

In the last months of bearing a child, women with multiple pregnancies often develop gestosis - late toxicosis, and they proceed very hard. In addition to the fact that more than one fetus develops in the uterus, it becomes very large due to the development of polyhydramnios, which often accompanies multiple pregnancies. This provokes a malfunction of the kidneys.

Often, childbirth occurs prematurely, and the more children a woman bears, the earlier childbirth can occur.

After caesarean section

The situation may be of particular danger if multiple pregnancy is not the first and develops immediately after the previous birth of children with the help of a caesarean section. The risk in this case is presented both for the woman and for the children that develop in her stomach. So, we list the main possible complications:

• There may be threats of premature birth;
• The fetus in the uterus may take the wrong position;
• The scar may indicate that a placental proposal will form, or the placenta will be located low enough. This threatens premature placental abruption with bleeding.
• Impaired circulation in the uterine wall where there is a scar after a caesarean section, especially if the placenta is attached to this area. This can cause a lack of oxygen and nutrients, which can lead to the development of intrauterine hypoxia.

signs

Diagnosis of multiple pregnancy at an early stage (before 28 weeks) is necessary in order to safely manage the pregnancy and to minimize the potential risk during childbirth. Diagnosis makes it possible to prevent various complications, as well as to plan childbirth to the maximum.

Examination of a woman with multiple pregnancy is carried out every 10 days, and in the last stages of gestation - every 5-7 days.

With multiple pregnancies, symptoms can be detected already at the first doctor's appointment. The specialist looks at the size of the uterus, which does not correspond to the deadline. At the same time, at the next visit, the uterus increases very quickly in size.

In order to determine whether this is multiple pregnancy or polyhydramnios, additional studies are prescribed. With the help of electrocardiography, the heart of several fetuses can be detected. This can be done starting from the 10th week of gestation.

Ultrasound makes it possible to see a multiple pregnancy already for a period of 9-11 weeks, but errors are quite likely. At a later stage, ultrasound can reveal that one of the fetuses is frozen, or, conversely, it will be possible to see another child that was not previously visible on ultrasound.

People who are far from obstetrics, having learned about the birth of twins or triplets, will only rejoice: you can suffer once and not give birth again. Gynecologists in this regard are not so optimistic, because multiple pregnancy threatens with early toxicosis, preeclampsia, complications during childbirth and other problems. However, in reality, things may not be so pessimistic.

What is multiple pregnancy

Multiple pregnancy is the simultaneous bearing of more than one fetus. Such children are called twins, twins, triplets, and so on. Most people know that twins are single or dizygotic. The former are always of the same sex and are very similar in appearance. The latter may be of different sexes and have only some common facial features. However, for an obstetrician, questions about gender or similarity are not significant, it is much more important to determine the number of fetuses.

Duzygotic

Bichorionic biamniotic twins are considered the most favorable. Each of these twins has its own bladder and placenta. Plus, if during the process of fertilization of the egg, the implantation of the embryos occurred to different walls of the uterus, for example, to the anterior and posterior. Provided that there are no complications, such children can be carried up to 38 weeks. The formation of dizygotic twins often occurs during different sexual intercourses, the interval between which was less than 1 week.

Identical pregnancy

Such children are born of the same sex with common facial features and a chromosome set. Depending on the stage of separation of the egg, monozygotic pregnancy is divided into several types according to the nature of placentation:

• Monochorionic monoamniotic - division occurs when the egg passes through the cervix. Babies develop in the same bladder and share a common placenta. The danger of such a pregnancy is the risk of developing fetofetal transfusion syndrome (placental insufficiency). In this case, delivery is performed up to 34 weeks.
• Monochorionic biamniotic - division occurred 3-8 days after conception. Babies share one placenta, but each has its own amniotic sac.
• Siamese twins - cell division occurred later than 13 days. Such twins live in the same bladder and have grown together with bodies in the region of the coccyx, skull, and thoracic region.

Probability of occurrence

According to various studies, the probability of multiple pregnancy when conceived naturally is no more than 2%. At the same time, more women expect the birth of dizygotic twins than same-sex twins. The likelihood of conception with many children increases when a woman reaches the age of 35, takes oral contraceptives, stimulates the ovaries and has a genetic predisposition.

If a multiple pregnancy occurred after undergoing an IVF procedure (in vitro fertilization), then the probability of giving birth to several children at once is 35-55%. This happens when several fertilized follicles are simultaneously planted in the uterus in order to increase the chances of survival of one of them. When implanting more than 3 eggs, embryo reduction is prescribed. This helps to prevent deviations in the development of other children.

Reasons for multiple pregnancy

It is difficult to carry and give birth to several babies, especially if the woman is no longer young or has a burdened obstetric analysis (one or more frozen embryos, premature termination). Doctors advise not to overestimate your capabilities and approach the birth of several babies with all responsibility, especially if the conception occurred after IVF. There are several reasons that can provoke the fertilization of several eggs at once.

Heredity

Genetic predisposition is considered the most indisputable factor in large conception. Science has proven that if there have already been cases of the birth of twins or triplets in the family, then the probability of a large pregnancy increases several times. Moreover, heredity can be transmitted through several generations or from indirect relatives - aunts, cousins.

Stimulation of ovulation

If a woman has previously been treated for infertility and at the same time took hormonal drugs that stimulate the maturation of follicles, for example, Clomiphene or Gonadotropin, then the risk of giving birth to twins or triplets increases. Even after the withdrawal of these drugs, the maturation of several follicles at the same time can be observed or double ovulation can be observed within one menstrual cycle.

Woman's age

Under the influence of hormonal changes in the pre-climatic syndrome in women over 35 years old, not one follicle can mature, but several at once, which increases the chances of a double conception. This phenomenon is especially prone to women who are not only older than 35 years old, but have already had experience of childbirth before. Doctors also note that in multiparous gestation of twins is easier.

Hormonal contraception

With prolonged use of oral hormonal contraceptives, the risk of giving birth to twins or triplets also increases. The action of these drugs is based on the accumulation effect. Birth control pills gradually suppress the occurrence of ovulation, affecting the work of the ovaries. However, if a woman stops taking medication, a withdrawal symptom occurs: the “sleeping” ovaries begin to work with a vengeance, producing several eggs at once.

in vitro fertilization

The essence of the IVF procedure is the introduction of already fertilized eggs into the woman's uterus, which are grown in a test tube. In one session, the doctor can plant from 1 to 4 follicles. This is necessary in order to increase the chances of success. Sometimes all the eggs take root and a multiple pregnancy occurs. If there are more than 4 engrafted follicles, in order to reduce the risk of complications, one or more embryos undergo resorption (removal).

Large number of births in the past

Very often, multiple pregnancy is recorded in women who have already given birth to one or more children. At the same time, it was noted that the more children in the family, the higher the probability of re-conception for the fertilization of two eggs. According to statistics, almost every 3rd woman who has 4 births has twins or triplets. This effect in medicine is called pregnancy parity.

How to identify multiple pregnancy in the early stages

The fact that a woman became pregnant, says a lot external signs: nausea in the morning, full breasts, protruding nipples, sudden changes in mood, change in taste preferences. However, all these signs of pregnancy do not indicate the amount of expected addition. There are a number of distinctive symptoms that will make it possible to suspect the presence of twins or triplets. Quantitative conception can also be determined by blood tests or ultrasound.

signs

Symptoms of twins or triplets begin to appear from the very first days. For example, a woman's sense of smell becomes more acute, she begins to react sharply to certain smells. may appear on the face dark spots. Other signs of multiple pregnancy in the early stages:

• early toxicosis and gestosis;
• fast fatiguability;
• swelling of the legs and arms;
• excessive weight gain;
• large belly;
• high blood pressure;
• large size of the uterus that does not correspond to the term;
• mismatch of the fetal head with the volume of the abdomen;
• listening to two heart rhythms.

ultrasound diagnostics

It is important for women to know: at what time it is possible to determine a multiple pregnancy in order to sign up for an ultrasound diagnostic procedure in time. As a rule, it is prescribed at about 5-6 weeks to confirm the diagnosis. Starting from 10 to 12 weeks, using ultrasound, the doctor can determine whether or not the babies have malformations, determine the chorionicity (the number of placentas). It is possible to reliably calculate the number of placentas only until the 16th week, later it will be problematic to do this.

Determination of the concentration of hCG and lactogen in the blood

The very first hormone that begins to be actively produced by a woman's body after conception is human chorionic gonadotropin (hCG). It is synthesized by the cells of the embryo, and after the placenta. The production of hCG and progesterone begins approximately 7-8 days after conception and gradually increases over 5-6 weeks. You can determine the level of the hormone using a blood or urine test.

Placental lactogen is produced by the placenta. Its level begins to increase from 4-5 weeks of pregnancy and increases to 33-34 weeks. Normally, the level of this hormone is 0.05 mg / l in the early stages and 11.7 mg / l at 38-40 weeks. An increase in the level of lactogen and hCG in the blood by two or three times gives reason to suspect that a woman has a large pregnancy.

It can be difficult for some women to endure and give birth to one healthy baby normally, and multiple pregnancy carries an even greater burden on the body. When establishing the fact of the presence of twins or triplets, doctors warn their patients about the possibility of the following aggravated symptoms:

• early toxicosis. This symptom appears earlier than during normal pregnancy, is more severe and lasts up to 16-17 weeks.
• Significant weight gain. This is due to the doubling of the body's needs for nutrition and the normal development of children.
• Edema and shortness of breath. As the term increases, the load on all internal organs increases. The uterus begins to shift, compresses the stomach, lungs. That is why many women suffer from edema, shortness of breath and get tired quickly even without physical exertion.
• Gestosis. This symptom is diagnosed more often with twins or triplets than with expecting a single child, and it develops earlier and is more difficult.
• There is a risk of developing iron deficiency anemia and postpartum hemorrhage, early discharge of amniotic fluid, miscarriage.

Management of multiple pregnancies

Women who are expecting a large addition to the family should not only know how long a pregnancy with many children can be determined, but also when to register. To identify early malformations, such as down syndrome and other abnormalities, you need to be tested by a doctor before 8-10 weeks. In addition, maternity leave is given to expectant mothers of twins not at week 30, but at week 28, but sick leave issued for 160 days.

Gynecologist's consultations

Patients with twins require more careful monitoring, so they should visit the doctor more often: 2 times a month until 28 weeks, then 1 time in 7-10 days. In addition to the gynecologist, this type of pregnancy will be monitored by a therapist, who will have to be visited only 3 times during the entire gestation period. In the presence of estrogenital pathology, other specialists join the diagnosis and management of the patient.

Hardware diagnostics

In addition to taking tests to determine the level of hCG in the blood, a woman must undergo an ultrasound examination. In the early stages, this procedure helps to establish the presence of conception, and in the middle of the cycle, the presence of the slightest deviations. Ultrasound is carried out according to the schedule: at 22-24 and 32-34 weeks. In addition, a woman is prescribed:

• In the second trimester, the expectant mother is subjected to an echographic assessment. The ECG procedure gives an idea of ​​the state of cardio-vascular system mother.
• Approximately 25-28 weeks. a woman should have a CTG (cardiotography). This method allows you to control the fetal heartbeat.
• Between 15 and 20 weeks a triple test is prescribed - a blood test for the level of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG) and free estriol (EZ). This technique helps to establish at an early stage chromosomal abnormalities Key words: Down syndrome, Edwards disease, neural tube defects.

Diet

Such mothers should pay special attention to nutrition, since the body's need for vitamins, trace elements, proteins, carbohydrates and fats doubles, or even triples. Weight gain in expecting twins can reach 20 kg, so the daily caloric intake should be increased to 4000-4500 kilocalories. Poor nutrition can lead to fetal fading, miscarriage and complications.

Reception of vitamin and mineral complexes

Given the increased demands of the body for vitamins, useful micro and macro elements, doctors recommend starting to take vitamin and mineral complexes from the moment the fact of fertilization is confirmed. Around week 12, the doctor prescribes folic acid tablets or iron-containing drugs to prevent the development of anemia, a malformation of the spinal cord or brain in children.

Possible Complications

In addition to the above features of the load on the body, a twin pregnancy or expectation of triplets can have such specific complications:

• Anembryony is the death of a single embryo. This malformation occurs in 20% of cases, and its causes have not been reliably established.
• Fetofetal transfusion or placental insufficiency. It develops against the background of the monochorionic monoamniotic type, when one child lives and feeds at the expense of another.
• Congenital deformities in one or both twins - fusion of the body, disproportionate structure of the skull, intrauterine growth retardation, the presence of heart defects, the appearance of acute hypoxia of one fetus.
• Cerebral palsy - develops against the background of oxygen deficiency. It can have varying degrees of severity from strabismus in one of the twins to complete paralysis of the limbs.

Childbirth with multiple pregnancy

Women expecting twins are hospitalized 14-20 days before the expected birth. In this case, the method of delivery will be determined in advance based on the results of tests, the condition of the mother and children. When expecting twins, there is a high risk of giving birth to premature babies with low birth weight, who quickly adapt to the environment and can breathe on their own.

Terms of delivery

Multiple pregnancy of shorter duration than usual. It is not 280 days, but 238-266 days. It happens that during gestation one fetus dies. If this happened at an early date, then the gestation is extended. When expecting two babies, a woman, as a rule, safely bears and gives birth to a second. If one of the embryos died after 28 weeks, the doctor prescribes an emergency delivery, because the risk of death of the second crumb is high.

natural childbirth

The method of childbirth depends on many factors, but the position of the babies in the mother's tummy, especially the first one, plays a leading role. Natural childbirth is allowed if both babies are presented with heads, the condition of the mother and children is stable, and contractions are regular. With head presentation of the first and pelvic presentation of the second, natural childbirth is also possible, during which the second fetus is externally rotated under the control of an ultrasound machine.

Indications for operative delivery

A large percentage of perinatal mortality is represented by the birth of monochorionic monoamniotic twins, when, in addition to specific complications, umbilical cord torsion is often observed. The optimal delivery tactic for this type of multiple pregnancy is considered C-section. In the same way, fused twins are removed, with late diagnosis of pathology. Other indications for emergency caesarean are:

• severe overstretching of the uterus due to the large weight of children;
• polyhydramnios;
• the presence of three or more embryos;
• persistent weakness of labor activity;
• loss of small parts of the fetus;
• detachment of placental tissue;
• if the end of the umbilical cord wrapped around the fetus;
• intrauterine hypoxia of one of the fetuses;
• anomaly of labor activity;
• the presence of a scar on the uterus;
• with a low location of the placenta;
• collision of fruits (clutch by heads);
• breech presentation;
• transverse position of the twins.

Video

After reading an article about chance of multiple pregnancy you will learn:

• 1

  What are the types of multiple pregnancy;

• 2

  How are identical and multi-egg twins formed?

• 3

  How are twins different from twins?

• 4

  How does the number of placentas and amniotic sacs affect the course of pregnancy;

• 5

  The likelihood of multiple pregnancy;

• 6

  What factors contribute to the occurrence of multiple pregnancy;

• 7

  Diagnosis of multiple pregnancy;

• 8

  Features of the course of multiple pregnancy;

• 9

  What a woman with multiple pregnancies should know.

Now let's figure out what twins are, depending on the mechanism of their occurrence. So, if two eggs are fertilized, then dizygotic (two-egg) pregnancy. If spontaneous division of the zygote occurs after the usual fertilization of one egg, then monozygotic (identical) multiple pregnancy.

Children born from twins are called " twins"(in foreign literature -" fraternal" or " not identical”), and children from identical twins - twins (in foreign literature -“ identical").Among all multiple pregnancies, the frequency of twins is about 70%. Twins are always of the same sex and are like two drops of water similar to each other, because they develop from the same fetal egg and have exactly the same set of genes. Twins can be of different sexes and are similar only as ordinary siblings, since they develop from different eggs, and, therefore, have a different set of genes.

A twin pregnancy develops as a result of the fertilization of two eggs at the same time, which are implanted in different parts of the uterus. Quite often, the formation of fraternal twins occurs as a result of two different sexual intercourses, carried out with a small interval between each other - no more than a week.

Also, fraternal twins can be conceived in the course of one sexual intercourse, but on the condition that the simultaneous maturation and release of two eggs, both from one and from different ovaries, has occurred. Also, multiple pregnancy is divided by the number of placentas (chorion) and fetal bladders (amnion) into monochorionic, bichorial, monoamniotic, biamniotic.

Types of placentation in multiple pregnancy. a — bichorionic biamniotic twins; b - monochorionic biamniotic twins; c — monochorionic monoamniotic twins.

With fraternal twins, each fetus necessarily has its own placenta and its own fetal bladder. The position of the fetuses, when each of them has its own placenta and fetal bladder, is called bichorionic biamniotic twins. That is, in the uterus there are simultaneously two placentas (bichorionic twins) and two fetal bladders (biamniotic twins), in each of which the child grows and develops.

Identical twins develop from one fetal egg, which after fertilization is divided into two cells, each of which gives rise to a separate organism. With identical twins, the number of placentas and fetal bladders depends on the period of separation of a single fertilized egg. If separation occurs during the first three days after fertilization, while the fetal egg is in the fallopian tube and has not attached to the wall of the uterus, then two placentas and two separate fetal sacs will form. In this case, there will be two fetuses in the uterus in two separate fetal bladders, each feeding on its own placenta.

Such twins are called bichorionic (two placentas) biamniotic (two amniotic sacs). If the fetal egg divides 3-8 days after fertilization, that is, at the stage of attachment to the uterine wall, then two fetuses are formed, two fetal bladders, but one placenta for two. In this case, each twin will be in its own fetal bladder, but they will eat from one placenta, from which two umbilical cords will depart.

This variant of twins is called monochorionic (one placenta) biamniotic (two amniotic sacs). If the fertilized egg divides on the 8th - 13th day after fertilization, then two fetuses will form, but one placenta and one fetal bladder. In this case, both fetuses will be in one for two fetal bladder, and eat from one placenta. Such twins are called monochorionic (one placenta) monoamniotic (one amniotic sac). If the fetal egg divides later than 13 days after fertilization, then as a result of this, Siamese twins develop, which are fused with different parts of the body.

From the point of view of safety and normal development of the fetus the best option are bichorionic biamniotic twins, both identical and dizygotic. Monochorionic biamniotic twins develop worse and the risk of pregnancy complications is higher. And the most unfavorable option for twins are monochorionic monoamniotic.

The likelihood of multiple pregnancy

But there are a number of predisposing factors in which the occurrence of twins is more likely.:

1. hereditary predisposition. It has been proven that the presence of multiple pregnancy in the family, both maternal and paternal, increases the likelihood of twins. The ability to conceive twins is transmitted only through the female line. Men can pass it on to their daughters, but there is no noticeable frequency of twins in the offspring of men themselves. If there are already twins in the family, then the probability of giving birth to another pair is quite high, but it decreases with the distance in time of the generation of twins.
2. Mother's age. After 35 years, a change in the hormonal background begins, preceding menopause. Menses become irregular. And after several months of amenorrhea, the ovaries can produce more sex hormones compensatory, resulting in an increase in the level of follicle-stimulating hormone (FSH), and several eggs mature in one cycle, which leads to a multiple pregnancy.
3. Long-term use of oral contraceptives. In the course of observations, it was noted that if pregnancy occurs in the first cycle after the abolition of oral contraceptives, if they were taken for more than 6 months, then it is likely that it will be multiple. This is due to the same compensatory function of the ovaries. After all, during the reception hormonal drugs the ovaries do not produce their own hormones, but are at rest.
4. Stimulation of ovulation. If during the treatment of infertility in a woman drugs are used to stimulate ovulation (Clomiphene, Klostilbegit, etc.), the probability of multiple pregnancy increases to 6 - 8%. If at the same time preparations containing gonadotropin are used, then the probability of twins is already 25 - 35%.
5. Pregnancy resulting from assisted reproductive technologies. With IVF (in vitro fertilization), the occurrence of multiple pregnancies occurs quite often. And this has its justification. Since the IVF procedure has its own technical difficulties in performing, it is expensive, if it is ineffective, the money is not returned to the patient, then during its implementation, the woman is implanted not one embryo, but several, from 2 to 6 (usually 3) . Only one can take root, but all can. Therefore, with in vitro fertilization, multiple pregnancy occurs in 35-40% of cases.
6. short menstrual cycle and irregular shape uterus. There is also the effect of the duration of the menstrual cycle on the conception of twins. The greatest ability to give birth to twins are women whose menstrual cycle is very short - 20-21 days, as well as women with anomalies in the development of the uterus, for example, if there is a septum in the uterine cavity or with a bicornuate, as it were, bifurcated uterus.
7. Season. It is noted that the length of daylight hours affects the amount of hormones produced. Therefore, the occurrence of twins is more often noted during fertilization in spring and summer, when the day becomes longer.
8. Subsequent births. With each subsequent birth, the likelihood of having twins increases. So, after the second birth - twice, after the third - three times.
9. The nature of nutrition. To date, no link has been proven between the intake of certain foods and the occurrence of multiple pregnancies. But the opposite has been precisely proven - with a nutritional deficiency, with a diet poor in proteins, multiple pregnancy does not occur.
10. There is an inexplicable pattern of more frequent birth of twins during various social upheavals and wars. Most likely, the laws of population regulation are included here to preserve the biological species.

To date, with the available ultrasound examination and the possibility of determining multiple pregnancies in the early stages, there is no need for indirect signs of pregnancy, which appear already at later dates.Ultrasound diagnosis of multiple pregnancy is possible in the early stages of pregnancy (4-5 weeks) and is based on the visualization of several fetal eggs and embryos in the uterine cavity.

With multiple pregnancy, early (in the first trimester) determination of chorionicity (the number of placentas) is of decisive importance. This is necessary to select the optimal tactics for managing pregnancy and childbirth.

It is chorionality (and not zygosity) that determines the course of pregnancy, its outcomes, perinatal morbidity and perinatal mortality. The most unfavorable in terms of perinatal complications is monochorionic multiple pregnancy, which is observed in 65% of cases of identical twins. Perinatal mortality in monochorionic twins, regardless of zygosity, is 3-4 times higher than that in bichorionic twins.

Features of the course of multiple pregnancy

Multiple pregnancies are very different from singletons. At the same time, in women with multiple pregnancies, rapid fatigue, shortness of breath, constipation are more pronounced, and severe toxicosis often occurs in the first trimester of pregnancy. At a later date, the pregnant woman is rapidly gaining weight. The uterus at the same time reaches a very large size, exerting strong pressure on the abdominal organs. Late gestosis occurs much more often: pronounced swelling of the legs appears, blood pressure rises, and protein in the urine may appear.

The length of a multiple pregnancy also differs from that of a single pregnancy. The more fetuses, the earlier the birth occurs. So, the duration of pregnancy with twins is on average 37 weeks; with triplets - 35 weeks.

What a woman with multiple pregnancies should know

In multiple pregnancies, A balanced, nutritious diet plays an important role(3500 kcal per day).

At the same time, prophylactic intake of iron and folic acid preparations for at least 3 months is mandatory, since all the iron from the depot reserves is used for the development of several babies. And its deficiency leads to a delay in intrauterine development of the fetus.

The total weight gain during pregnancy should be at least 18-20 kg, while importance has an increase in weight in the first half of pregnancy (at least 10 kg) to ensure the physiological growth of the fetus.

The risks of miscarriage in multiple pregnancies are much higher, therefore, it is necessary to observe a protective regimen, including a decrease in physical activity, mandatory daily rest (three times for 1-2 hours).

Pregnant women with monochorionic twins should be screened, including ultrasound, more frequently than those with bichorionic twins to detect early signs syndrome of fetofetal blood transfusion. If this complication is identified, surgical correction is possible.

Despite the rather high modern level of development of obstetrics and obstetrics, women with multiple pregnancies are still at high risk. The management of multiple pregnancies and childbirth itself are significantly different from conventional pregnancy with one fetus. They require experience and in-depth knowledge of the condition from medical personnel.

Relevance of the topic

Features of multiple pregnancy determine the relevance of the problem for obstetrics in general and, in particular, for obstetrics of the perinatal period (from 22 weeks of intrauterine development to 28 weeks postpartum). These features are a high percentage of complications, prematurity and the risk of preterm birth, severe form of placental insufficiency, fetal malnutrition and intrauterine hypoxia, the possibility of severe malformations, etc.

Perinatal mortality in multiple pregnancies, compared with single pregnancies, is about 10% and is largely related to the body weight of the fetus. Malformations are registered 2 times more often, intrauterine mortality is 3-4 times higher, and over the past 30 years it has practically not decreased. Development frequency cerebral palsy in a child, twins are 3-7 times more often, triplets - 10 times, and the number of complications in the mother throughout the entire period of pregnancy - 2 or more times (up to 10).

Causes of multiple pregnancy

The development of two or more fetuses in the female body is called multiple pregnancy. Over the past 20 years, it has doubled, and women with multiple pregnancy among all pregnant women accounted for 0.7-1.5%, the birth of twins in relation to the number of all births - 1: 87, triplets - 1: 6,400, quadruples - 1: 51,000.

Many causes of multiple pregnancy have been noted, which indicates that this issue is still insufficiently studied. The likelihood of multiple pregnancy is largely determined by the following factors:

1. Heredity, that is, if the spouses or one of them comes from a multiple pregnancy or in their families, especially in the female line, there were similar cases.
2. An increased content of follicle-stimulating hormone in the blood of a woman, which contributes to the development and maturation of two or more eggs at the same time. This may be due to heredity, taking drugs that stimulate ovulation in the treatment of infertility, pregnancy immediately after the abolition of ok (), especially against the background of the use of ovulatory stimulation.
3. Conducting in vitro fertilization (), the program of which includes drug-induced ovarian hyperstimulation to obtain a large number of mature eggs. Multiple pregnancy with IVF is also due to the planting of several fertilized eggs in the uterine cavity, the possibility of implantation and development of more than one.
4. The number of births: with repeated pregnancy and childbirth, the likelihood of multiple pregnancies increases.
5. Women over 35 years of age. This is thought to be due to reduced fertility at this age due to the lack of monthly ovulation. As a result of this, there is an accumulation of hormones and their effect in the form of ovulation of two or more eggs.
6. Anomalies in the development of internal genital organs.

Many causes of multiple pregnancy, the main of which are listed above, indicate that this issue is still insufficiently studied.

Classification of multiple pregnancy

Zygosity, chorionicity, and the number of amniotic cavities are of considerable importance in resolving questions about the tactics of conducting such a pregnancy and childbirth. A zygote is a cell formed from the fusion of an egg with a sperm and containing a complete double set of chromosomes. Chorion is one of the three (outer) membranes of the fetus. The amniotic cavity is a cavity bounded by an aqueous membrane (amnion) and filled with amniotic fluid.

monozygotic

In accordance with the number of fetuses, pregnancy is distinguished by twins, triplets, etc. About 30% of twins are formed from one fertilized egg. Later, as a result of its division, two structures similar to each other develop, which have the opportunity to develop independently, individually. This kind of twins is called monozygotic, or identical, and children are called twins. They have the same gender, eye and hair color, skin pattern of the fingers, blood type, location and shape of the teeth.

Bizygous

Simultaneous maturation and release of two or more eggs can occur both in one ovary, and in both during one menstrual cycle. Bizygous, or dizygotic, embryos develop from two fertilized eggs and average 70%. Children are called "twins". They can be either same-sex or different-sex, with the same or different blood types, and be in the same genetic relationship. In cases of a larger number (triplets, quadruplets, etc.), both monozygosity and dizygosity are possible in various combinations.

Each of the dizygotic embryos has its own chorionic/placental and amniotic membranes. Each embryo has its own placenta. Thus, a four-layer septum is formed between the two embryos, consisting of sections of two chorionic / placental and two amniotic membranes. Therefore, such embryos in the classification are called di- (or bi-)-chorial, diamniotic dizygotic twins.

The formation of identical twins occurs when early stages development, division and transformation of a fertilized egg and depends on the time of these processes:

1. If the division of the egg occurs within the first 72 hours, counting from the moment of fertilization, that is, before the formation of the inner cell layer and the change in the cells of the outer layer of the egg, then two chorions and two amniotic cavities develop. As a result, a dichorionic, diamniotic monozygotic twin is formed, which may have one placenta formed from the fusion of two placentas, or two separate placentas.
2. If the division of the egg occurs within 4-8 days after its fertilization, when the formation of the inner cell layer has already ended, and the laying of the chorion has occurred from the outer layer, but the amniotic membranes have not yet been laid, then each embryo will develop in a separate amniotic cavity. Thus, embryos with individual water sacs will be surrounded by one common chorion, resulting in the development of diamniotic, monochorionic monozygotic twins.
3. If the laying of the amniotic membrane has already taken place by the time of separation of the fetal egg, which usually occurs by the 8th day after the fusion of the egg with the sperm, then this will lead to the development of embryos with a common water sac and one chorion - monoamniotic, monochorionic monozygotic twins.
4. The division of a fertilized egg at a later date (after 13 days), when the embryonic disc has already formed, will be only partial. This will lead to the development of twins fused together.

The easiest way to determine if you are monozygotic or dizygotic is to be examined by an obstetrician after the birth of children. The septum between the twins consists of two water (amniotic) membranes, and between the "twins" - of four: two amniotic and two chorionic.

Features of the course of multiple pregnancy

Possible complications for the mother

Pregnancy with two or more fetuses, especially with their different blood types, in comparison with a singleton, makes higher demands on the woman's body. In addition, the course of the dichorionic type is more severe than that of the monochorionic type. The average gestation period for twins is about 37 weeks, for triplets - 35 weeks.

In the body of a pregnant woman, the volume of circulating blood increases (by 50-60%), which creates an additional burden on cardiac function, while with one fetus this figure does not exceed 40-50%. Due to hemodilution (blood dilution), anemia, an increased need for vitamins, macro- and microelements, especially folic acid and iron, are often noted.

Women are much more likely to notice shortness of breath, fatigue, painful heartburn, urination disorders and constipation. These phenomena are especially disturbing in the last stages. In addition, toxicosis among them are more common, develop earlier, and their course is more severe. The uterus reaches a large size not only because of multiple pregnancy, but also as a result of cases of frequent development of polyhydramnios, which can cause impaired renal function. The number of premature births is directly dependent on the number of fetuses and ranges from 25 to 50%.

A very common problem is isthmic-cervical insufficiency (ICI) in multiple pregnancies. It develops much more often than with a singleton, especially in the presence of triplets or more, which is associated with the influence of a mechanical factor (increased pressure in the uterine cavity and its stretching). ICI usually begins to develop after the 22nd week and is characterized by rapid progression. If with twin surgical treatment effective in strengthening the cervix, then as the triplets grow, etc., the sutures often do not withstand the load and cut through. Therefore, in some cases, the additional use of a special pessary helps.

With multiple pregnancies, chronic somatic diseases. special attention and strict ongoing dynamic monitoring requires multiple pregnancy after caesarean section, due to the large number of risks, both for the fetus and for the woman. The main risks with high frequency include:

• disorders of the placental circulation due to a violation of the vascular network of the uterus after surgery, which leads to intrauterine growth retardation and / or intrauterine asphyxia;
• placenta previa;
• the threat of termination of pregnancy;
• incorrect position of the fetus;
• failure of the scar on the uterus and its rupture, which is the most dangerous.

In some cases, with multiple pregnancy, as with a singleton, on the 8th day, bloody issues from the vagina, lasting about 4 days - this is usually a slight implantation bleeding that accompanies the introduction (implantation) of a fertilized egg into the uterine mucosa. However, when two or more of these eggs are implanted, it can be longer, repeated and abundant and lead to spontaneous miscarriage. In these cases, it is necessary to differential diagnosis and treatment in a hospital setting, where assistance is provided in the form of hemostatic therapy, rest, prescription of antispasmodics, etc.

Risks to the fetus(es)

Compared with a singleton pregnancy, the developmental delay of one fetus in a multiple pregnancy is 10 times more common and amounts to 20% for dichorionic twins, 30% for monochorionic twins, and the developmental delay of twins as a whole is 1.7% and 7.5%, respectively.

Of fundamental importance in the detection of congenital malformations in one of the fetuses is the definition during the prenatal period of zygosity, since in the case of dizygotic twins, the second fetus may be without pathology, and in case of monozygotic twins, the probability of defects in one of them is quite high. The probability of developing fetal structural anomalies in singleton pregnancy and dizygotic twins is the same, and in the case of monozygotic twins it is 2-3 times higher.

In order to detect fetal trisomy, which includes Down's disease, Edwards syndrome and Patau syndrome, a non-invasive prenatal test is performed, which has significant reliability. Its essence lies in the genetic study of DNA particles of fetuses in the venous blood of a woman at the 9th - 24th weeks. When positive result additional, but already invasive, genetic studies are being carried out. When the results are confirmed, the tactics of further management of pregnancy consists in its artificial termination.

In the monochorionic, much less frequently in the bichorial placenta, there are frequent cases of the formation of an arterio-arterial or arterio-venous anastomosis (connection between two arteries or between an artery and a vein). The second type is the most unfavorable, since in this case there is an outflow of blood from the artery of one fetus into the vein of another. In these cases, if the pressure in the system of placental vessels is symmetrical, the development of the fetus occurs under equal conditions. But with monozygotic twins, these conditions can be disturbed by asymmetric blood circulation in the placenta, resulting in the intake arterial blood to one of the fruits decreases, it does not receive sufficient nutrition and its development is delayed.

A significant imbalance in the system of placental vessels is the reason that almost all blood circulation passes to one of the twins - it is possible to develop feto-fetal transfusion syndrome (FFTS), which is noted especially in cases of monochorionic multiple pregnancy (from 5 to 25%), hypertension , expansion of the heart, etc. in one of the fetuses. The second may develop deformity, cessation of heart function, or it gradually dies and undergoes mummification (spontaneous reduction of the fetus). This process can be complicated by the development of a woman's DIC syndrome (disseminated intravascular coagulation), which threatens her life.

Fetal reduction in multiple pregnancy

In some cases, the reduction of the fetus is carried out artificially. The need for this is more often after IVF. Artificial reduction is associated with certain risks and complications, and therefore is performed if there are strict indications:

1. The need to reduce the number of fetuses implanted after IVF.
2. They have pathological changes.
3. Risk of miscarriage.
4. A woman has contraindications to carrying a multiple pregnancy.

The procedure for artificial reduction is usually carried out at a time not earlier than 7 and not later than 13 weeks. It consists in cardiac arrest of an unpromising fetus (or fetuses) by puncture injection of a special drug or air into his/their heart. To do this, transvaginally (at 7-8 weeks) or transabdominally (at 8-13 weeks) after local anesthesia a needle under the control of an ultrasound device is used to puncture the uterine cavity. In the future, resorption of the tissues of the fetus occurs.

How to sleep during multiple pregnancy?

Occurring in the third trimester in almost half of women with one fetus, the so-called inferior vena cava syndrome can complicate the course of pregnancy. With multiple pregnancy, it occurs earlier and can be much more difficult.

All venous blood from the lower half of the trunk and abdominal cavity is collected in a vein, then it enters the right atrium, etc. The cause of this syndrome is increased pressure in the abdominal cavity due to an increase in the uterus. When a woman is in a horizontal position on her back or on her right side, the inferior vena cava is compressed between the uterus and the spine.

Against the background of an increased volume of circulating blood and an increased need for a woman in the blood supply to the brain and heart, the flow of the required volume of blood to them during compression of the inferior vena cava is sharply reduced due to a decrease in the return of already arterial blood, and the blood supply to the fetus also suffers. For most, this goes unnoticed, but about 10% may experience symptoms such as a sharp decrease in blood pressure, dizziness, pallor, nausea, vomiting, and in severe cases, loss of consciousness and collapse, the appearance of convulsions are possible.

Blood circulation is quickly restored when the uterus is displaced by the hand to the left or as a result of turning the woman to the left side, which helps to release the inferior vena cava from compression. Therefore, being in a horizontal position, it is necessary to lie on the left side.

Signs of multiple pregnancy and its management

Multiple pregnancies in early pregnancy

Diagnostics

Wide application in clinical practice obstetrics and gynecology has made it possible to diagnose multiple pregnancies in the early stages. Prior to ultrasound, this diagnosis was often difficult. Basically, it was more or less reliable in the later stages, and sometimes only during childbirth.

How long is a multiple pregnancy?

An early assumption about the presence of two or more fetuses can be made on the basis of a set of signs:

• a history that the couple or their closest relatives are one of the twins or "twins";
• availability of data on ovulation hyperstimulation and IVF;
• early development and more severe course of induced hypertension, symptoms of toxicosis (vomiting, nausea), swelling of the mammary glands;
• discrepancy in the first trimester of the size of the uterus to the duration of pregnancy, which also occurs with or cystic skidding.

At a later date, in the formulation of a presumptive diagnosis, importance is attached to such data as:

• early stirring during multiple pregnancy, which can be felt by a woman from the 15th week, while in the first single pregnancy - from the 20th, and in subsequent ones - from the 18th week;
• the size of the circumference of the abdomen and the height of the fundus of the uterus, which exceed the expected duration of a singleton pregnancy;
• palpation through the anterior abdominal wall in the second half of gestation of balloting large parts of the fetus (heads and pelvis) in different parts of the abdomen;
• palpation of a large number of small parts;
• the presence in the middle sections of the bottom of the uterus of a depression formed by the protrusion of its corners by large fetal parts (with twins);
• auscultatory determination of two points of the heartbeat, especially if there is a zone of absence of tones between them (zone of "silence");
• different (difference of 10 beats) heart rate at different points, which can also be determined by means of cardiac monitors.

How to determine multiple pregnancy in the early stages more reliably?

In making such a diagnosis, to a certain extent, one can focus on the concentration in the blood of hCG (human chorionic gonadotropin) and placental lactogen. This laboratory biochemical testing is not completely reliable, but relatively informative. Thus, the level of hCG during multiple pregnancy at each stage of the gestational period exceeds the norm for a singleton pregnancy.

Of similar importance is the determination of the content of progesterone in the blood. Elevated progesterone in multiple pregnancies , compared with the norms defined for a singleton, will be in each respective trimester.

The main method of early diagnosis and a tool that helps prevent many complications of multiple pregnancy is ultrasound. The accuracy of this diagnostic method, including the earliest dates, is more than 99%. It is based on the visual identification of several fertilized eggs or embryos from the 5th to 6th week.

In addition, echography allows in the second and third trimesters to determine the nature of fetal development and the contours of the fetus, which helps to identify conjoined twins, FFTS, the location and number of placentas and amniotic (water) cavities, to identify congenital malformations, antenatal death, etc. according to echometric biometrics, the following five types of twin development are distinguished:

1. Physiological - both fruits.
2. Signs of malnutrition with uneven (dissociated) development.
3. Uneven development of both fetuses with a 10% difference from the body weight of the larger one.
4. Availability congenital pathology development.
5. Intrauterine death of one fetus.

Fruit presentation options

Ultrasound also allows you to establish the presentation of the fetus and their position, which is especially important before the onset of labor.

In addition to some of the above points (reduction, prevention of the syndrome of compression of the inferior vena cava, etc.), it provides for the prevention of preeclampsia, their early detection and treatment in a hospital, control of the blood coagulation system, the function of the cardiovascular system and kidney function.

Recommendations are also given on the correct balanced and sufficient high-calorie nutrition of a woman, folic acid intake of 0.001 grams per day and iron preparations (up to 100 mg) are prescribed. In addition, in order to prevent preterm birth, it is recommended to limit physical activity - staying in bed 3 times for 1-2 hours during the day, taking tocolytics and bed rest in case of a threat of preterm birth.

One of the ways to predict the resolution of pregnancy is the use of non-stress testing of the state of fetal heart function in response to their movement. The test should be done every week after the 30-week period. If possible, a blood flow study is also performed in each of the fetuses individually.

In case of an uncomplicated course of pregnancy, hospitalization in the maternity ward is necessary before the expected date of birth for 2-3 weeks in the presence of twins and a month for triplets. In the absence of the onset of labor activity for a period of 37 weeks, it is advisable to stimulate it, and in some cases, a planned caesarean section for a period of 37-38 weeks. The presence of a scar on the uterus with multiple pregnancies is a direct indication for a caesarean section.

The optimal method of delivery in the case of monochorionic and monoamniotic twins is caesarean section at 33-34 weeks (due to the high risk of umbilical cord torsion), and during pregnancy with 3 fetuses or more - at 34 weeks.

Childbirth and their management

The normal birth course is often accompanied by complications. In the first stage of labor, on average, 30% of women in labor have premature or earlier rupture of amniotic fluid. Moreover, it is often accompanied by the loss of small parts - loops of the umbilical cord, legs or handles.

Due to the overstretched uterus, the weakness of the generic forces develops, and the opening of the cervix is ​​significantly delayed. Often the duration of the period of expulsion of the first fetus also increases. The presenting part of the second tends to be inserted into the pelvis at the same time as the first, and this takes long time. Weakened and overstretched anterior muscles abdominal wall, because of which the straining period is lengthened or becomes impossible. All this leads to prolonged labor, which threatens infection of the uterine cavity and the development of hypoxia ( oxygen starvation) fruits.

During the period of expulsion of premature fetuses, there is a risk of rapid labor and perineal rupture. Prevention of this complication requires timely pudendal (perineal) anesthesia and perineal dissection.

A serious complication in the period of exile is premature detachment of the placenta, especially after the birth of the first child, which is associated with a sharp decrease in pressure inside the uterus and a decrease in its volume. This complication threatens with heavy bleeding and the development of hypoxia of the second child. To prevent it, the obstetrician performs an emergency opening of the second fetal bladder.

A very rare but severe complication is the adhesion of the heads to each other, as a result of which they tend to enter the small pelvis at the same time.

Birth management in multiple pregnancies

It consists in careful monitoring of the cardiac activity of the fetus with the help of heart monitors and the condition of the woman in labor. Keeping them in the first period is desirable on the left side for the prevention of inferior vena cava syndrome. With the development of weakness of the generic forces, the latter are stimulated by intravenous drip of a glucose solution with oxytocin, and anesthesia is performed by the method of epidural analgesia.

In case of development of weakness of labor activity and fetal hypoxia during the period of exile, obstetric operational aids are carried out in the form of obstetric forceps applied to the head (with cephalic presentation) or extraction (with breech presentation) by the pelvic end.

The ligation of the umbilical cord is carried out not only at the fetal end, but also at the maternal one, since after its dissection with monochorionic twins, the death of the second fetus is possible as a result of bleeding from the umbilical cord.

The birth of the second child should occur no later than 10-15 minutes after the first. Otherwise, the obstetrician opens the fetal bladder, and the amniotic fluid is slowly released, after which the birth is carried out naturally (in a longitudinal position).

In the case of a transverse position or incorrect insertion of the head of the second fetus into the small pelvis under general anesthesia turn on the leg and remove the child. If it is impossible to give birth naturally (impossibility of turning, a large child, cervical spasm, signs of acute hypoxia of one of the fetuses, prolapse of the umbilical cord and small parts, persistent secondary birth weakness), delivery is carried out by caesarean section. The best option delivery with triplets or more, as well as in the case of fusion of twins - caesarean section.

The succession period (before the separation of the placenta - the placenta with membranes) proceeds in the same way as in a singleton pregnancy. However, due to the overstretched uterus and a decrease in its tone, the frequency of delayed separation of the placenta and the associated heavy bleeding is much higher and more dangerous. Therefore, at the end of the second period, methylergometrine is administered intravenously, and after the birth of children, oxytocin is dripped for 2 hours. If there is no effect, manual separation of the placenta and subsequent massage of the uterus on the fist are carried out.

The frequency of complications in the postpartum period is also significantly higher. They are manifested by late postpartum hemorrhage, delayed reverse development of the uterus to its previous state (subinvolution), postpartum. Therefore, after childbirth, anti-inflammatory drugs and uterine contractions are prescribed.

Thus, despite the fact that multiple pregnancy is not a pathological condition, it requires heightened attention and a specific approach to each woman at every stage from conception to the postpartum period. Besides, special supervision and care of the born babies are necessary.

The birth of a new life in the female body is always a miracle. However, an even greater miracle is when the expectant mother finds out that the baby in the tummy is not alone at all. For many couples, this comes as a complete surprise, while others consciously want to give birth to twins. What is the specificity of multiple pregnancy, what risks does it carry? What should a woman prepare for?

Multiple pregnancy - what is it

In medicine, a pregnancy is considered multiple, in which more than two fetuses immediately develop in the uterus of the expectant mother. The most frequent option is twins - 1:87 in relation to conventional births with one child. Triplets and quadruplets are born much less often - respectively 1:6400 and 1:51000.

A unique case was recorded in 1998 in Saudi Arabia- seven twins were born there.

Interestingly, in different countries the frequency of multiple pregnancy is significantly different. For example, in China and Japan this is only 1-2 cases out of a thousand, but for Africa this option is more common - 10-15 cases per thousand births. As for Russia, over the past two decades, multiple pregnancies have been recorded twice as often.

More twins are born in African countries than in other continents

For a person, unlike animals, the bearing of two or more children at the same time is considered atypical, and therefore, some experts even perceive multiple pregnancy as a condition that is on the border of the norm and pathology. The reason for this is the increased load on the female body and the numerous risks for the development of babies.

Since ancient times, multiple pregnancy has been regarded as a miracle of nature and gave rise to many legends. For example, the ancient Greeks and Romans considered it a divine gift. Not without reason in ancient mythology pairs of twins appeared, having a royal origin or a divine nature. So, the names of the legendary Castor and Pollux became the names of the stars in the zodiac constellation of twins (they symbolize their heads).

In antiquity, multiple pregnancy was considered a blessed gift from the gods.

Classification of multiple pregnancy

There are two types of multiple pregnancy.

polyzygous

Polyzygous (or dizygotic, non-identical) multiple pregnancy occurs due to the fact that in the body of a woman two or more eggs are ovulated and subsequently fertilized. As a result, babies of the same or different sexes are born, having approximately 50% of common genetic characteristics (that is, just like ordinary blood brothers and sisters).

Fraternal twins can even differ greatly in appearance. Yes, in Kindergarten, where I once worked as an educator, there were two twin girls Lisa and Masha. Their mother was Russian, and their father was Uzbek. And what is surprising: one of the sisters was black-haired and swarthy with a typical Asian face, but the second was born a fair-skinned blonde with blue eyes.

Fraternal twins can be of different sexes and are not at all an exact copy of each other.

Each of the polyzygotic twins has its own water membrane (amnion), chorion (hairy membrane) and placenta. They are also called bichorial or biamniotic polyzygotic twins. The frequency of such multiple pregnancy is approximately 66% of cases.

Each of the fraternal twins has its own placenta, water and hairy membrane

The process of ovulation and subsequent fertilization of eggs can have its own nuances:

1. The eggs are released from different follicles of one or both ovaries. In this case, fertilization occurs at about the same time.
2. It is extremely rare that several eggs ovulate in the same follicle. They also fertilize at the same time.
3. The second egg ovulates and is fertilized some time after the first - against the background of an already developing pregnancy (the difference usually does not exceed a week).
4. Several eggs that mature in one cycle are able to be fertilized by the sperm of different sexual partners.

monozygotic

A rarer case (33%) is the splitting of one fertilized egg. As a result, two fetuses are formed (sometimes more), which are genetically absolutely identical. These babies are always same-sex, have the same facial features (an exact copy of each other), physiological features, mental abilities, temperament, psychology, etc. Brothers or sisters even have an identical arrangement and shape of teeth; in childhood, they get sick almost simultaneously. It is well known that twins are connected by an inextricable emotional bond (this is not surprising, because initially they were one ovum).

Identical twins are absolutely identical at the genetic level, because they were once a single organism.

Interestingly, the formation of monozygotic twins largely depends on the specific period at which the separation of the fetal egg occurred:

1. First 72 hours. The inner layer of zygote cells has not yet been formed, and the outer one has not changed either. Therefore, two chorions are formed with two separate amniotic cavities (bichorial or biamniotic monozygotic twins). In this case, the placenta is common or two separate ones are formed.
2. First 4-8 days. During this period, the inner cell layer is already formed, the chorion is laid. However, the amniotic membranes are not yet formed, so the development of the embryos will proceed in separate amniotic cavities (water sacs). Such twins are already called monoamniotic, monochorionic monozygotic twins.
3. After 13 days. The division of the fetal egg at such a late date will be only partial. After all, the embryonic disc is already formed. As a result, an anomaly will arise - children will be born, fused together.

If a woman is pregnant with triplets (or even more fetuses in her uterus), then monozygosity and polyzygosity are often combined in different combinations. For example, two identical twins and one identical twin may be born.

Video: why twins are born (Elena Malysheva's TV program “Live great!”)

Factors provoking multiple pregnancy

Many factors contribute to multiple pregnancy. Nonetheless this question in medicine is not yet well understood.

Causes of polyzygotic pregnancy:

1. Stimulation of ovulation, when the female ovaries for some reason do not produce follicles themselves. As a result, the organs begin to work hard, producing several eggs at once, capable of fertilization, in one cycle.
2. Conducting IVF. The program of this procedure provides for ovarian hyperstimulation. As a result, several eggs are formed. To increase a woman's chances of pregnancy, two or more embryos are placed in her uterus. Often only one of them takes root, but sometimes all at once.
3. Hereditary predisposition to periodic maturation in the same cycle of more than two eggs.
4. Number of births. With each subsequent pregnancy, the chances of conceiving twins increase.
5. The woman is over 35 years old. The number of anovulatory cycles is increasing. However, hormones accumulate, and at some point two eggs can mature at once.
6. Taking hormonal contraceptives with their subsequent cancellation. After that, hormones often begin to be produced with double strength.

IVF fertilizes multiple eggs

Monozygotic pregnancy is provoked by several other factors:

1. Influence of toxic substances.
2. Violation of the ionic composition of the medium.
3. Lack of oxygen.
4. delayed implantation.
5. The woman is over 30 years old.
6. hereditary predisposition.

Signs and diagnosis of multiple pregnancy

In the early stages, only ultrasound can accurately determine multiple pregnancy. So, already for a period of five weeks in the uterus, you can see two (or more) embryos, as well as differentiate multiple pregnancy from cystic drift or fibroids.

Before the advent of ultrasound, it was quite difficult to diagnose multiple pregnancies. This could be reliably done only in the later stages, and sometimes only in the process of childbirth.

In addition, the presence of twins can be suspected by too high a level of the hCG hormone in the blood, which does not correspond to the gestational age. At the same time, progesterone will also be increased.

Table: hCG norms during pregnancy with twins and one fetus

A mother-to-be may suspect that she is pregnant with twins even from the results of a routine pregnancy test. The treasured second strip will become bright too early, sometimes even before the delay. This is due again to a high level of hCG, but already in the urine.

With multiple pregnancies, the second strip can become bright very early

When the doctor examines the expectant mother on the gynecological chair, the uterus will be too large due to the presence of two embryos: the size does not correspond to the delay in menstruation.

Another sign of multiple pregnancy in the early stages is too pronounced toxicosis (this is severe nausea, vomiting, aversion to smells) and very swollen mammary glands (although, of course, some people have this condition even with a standard pregnancy with one fetus).

As for the second trimester of gestation, the following signs are characteristic of multiple pregnancy:

1. There is a sharp growth of the uterus. The circumference of the abdomen will significantly exceed the norm characteristic for bearing one child. In addition, the height of the bottom of the organ will be greater.
2. By palpation, the doctor can determine the large parts of the fetus (these are two heads, two basins), as well as many small parts.
3. In two different areas of the abdomen, a heartbeat is heard, and there will be a silent zone between them. Moreover, the frequency of fetal heart beats often varies (up to ten beats per minute).
4. A woman may feel a stir too early. The reason for this is that the amount of free space in the uterus is rapidly decreasing, and even slight movements of the fetus can be recorded. So, if during the first singleton pregnancy, stirring begins at about 20 weeks, with the second - from 18 weeks, then when waiting for twins, movements can be felt already from 15 weeks.

With multiple pregnancies, a woman usually feels the first movements much earlier.

Ultrasound examination when carrying twins is also carried out in the second and third trimester. It makes it possible to assess the nature of fetal development: the number of placentas, the uniformity of the development of babies, to fix conjoined twins.

The specifics of the course of pregnancy in a woman carrying twins

Multiple pregnancy often becomes a test for female body. Indeed, in comparison with the usual one, it imposes more stringent requirements on health.

All patients expecting twins should visit the antenatal clinic more frequently than is necessary for a singleton pregnancy.

The duration of pregnancy is inversely proportional to the number of fetuses. For example, with twins it will be about 37 weeks, with triplets it will be already 35 weeks (the period of bearing one child is the standard 40 weeks). This is due to the fact that the overstretched uterus is becoming increasingly difficult to hold babies.

When expecting twins, all the possible “charms” of pregnancy, including complications, a woman begins to feel earlier, while they are more pronounced:

1. Toxicosis. Appears earlier than in normal pregnancy. It is more difficult and lasts until the 17th week (when bearing one child, it ends by the 13th week).
2. As the fetus grows, the enlarged uterus provokes a displacement of the diaphragm. The heart of the expectant mother suffers from this: she begins to feel early cardiopalmus, weakness, shortness of breath, fatigue.
3. The growing uterus compresses the stomach and intestines. The result is constipation, belching, heartburn already in the early stages.
4. Clamping of the inferior vena cava leads to early varicose veins.
5. Squeezing the bladder provokes more frequent urination (even in the second trimester, when in this regard a woman bearing a single fetus experiences some relief).
6. In the body of a woman, the volume of circulating blood increases. If during the bearing of one child this figure is 40–50%, then with a multiple child it is already 50–60%. As a result, there is a lack of vitamins and macronutrients, especially iron. Therefore, early anemia almost always accompanies women expecting twins: they have to take medications throughout their pregnancy.
7. When carrying two fetuses, the risk of developing polyhydramnios is higher, and this negatively affects the kidneys of the expectant mother.
8. Preeclampsia. If during normal pregnancy 30% of expectant mothers face it, then with multiple pregnancy it is already 50%.
9. All those expecting twins in the second half of pregnancy experience edema, there is arterial hypertension. So the body responds to the growing needs of the fetus.
10. Gestational diabetes is more common.
11. If before pregnancy there was a certain chronic illness, then it is necessarily aggravated, because the body is under great stress.
12. If the twins are fraternal, then the likelihood of incompatibility of the blood of the mother and fetus increases. After all, they may well have a different group and Rh factor.
13. With multiple pregnancy, isthmic-cervical insufficiency very often occurs - a pathology in which the cervix opens slightly before childbirth (especially if the woman has already given birth). This is due to a mechanical factor: a large volume and mass of the uterus, its overstretching. Developing given state already after 22 weeks and rapidly progressing. The expectant mother is stitched on the cervix, and if she expects triplets, then a special pessary is additionally used (since the stitches can cut through from the load).
14. When two or more placentas are attached to the uterus, one of them may be low or a presentation occurs.

Photo gallery: the specifics of the course of multiple pregnancy

With multiple pregnancies, edema cannot be avoided. Women bearing twins suffer from anemia with early dates With multiple pregnancy, varicose veins are more likely and occur earlier due to early clamping of the inferior vena cava With multiple pregnancy, toxicosis begins earlier, ends later and is more difficult One of the placentas in the uterus may be located too low

An expectant mother who is expecting twins (and even more so triplets) is in dire need of enhanced nutrition. If an ordinary pregnant woman should receive about 2500 kcal per day, then expecting twins - at least 4500 kcal. In addition, you need not just to saturate the body (lean on flour products), but to eat food rich in nutrients. During pregnancy, such a woman usually gains 16–21 kg, but if the fetus alone, this figure is 9–14 kg.

To prevent premature birth, the gynecologist usually recommends limiting physical activity: in addition to nighttime sleep, the expectant mother needs to lie more during the day. With the threat of premature birth, bed rest is mandatory.

Particular attention should be paid to multiple pregnancies after a caesarean section. There are two main dangers here:

1. Rupture of the scar due to too much stress on the uterus.
2. Premature placental abruption or placenta previa.

Multiple pregnancy after a caesarean section involves artificial delivery.

Features of delivery in multiple pregnancy

The birth of a patient carrying twins is fraught with increased risks. They require the presence of a larger number of medical personnel (two midwives, two neonatologists), highly qualified doctors, and a clear orientation of doctors in a situation where certain manipulations need to be urgently performed.

Perinatal mortality in multiple pregnancies is higher than in the bearing of one child, 3-4 times (approximately 10%). However, this is primarily due to the complicated course of pregnancy itself and an insufficiently detailed approach to delivery.

Given the expected due date (it occurs earlier than when carrying one child), a woman is sent to the hospital in advance: with twins - in a couple of weeks, with triplets - in a whole month. If labor activity does not begin at a period of 37 weeks (35 weeks - with triplets), then it is advisable to carry out artificial stimulation.

Especially carefully you need to monitor the condition of identical twins: this is due to the high probability of torsion of the umbilical cord. Therefore, such patients sometimes have a caesarean section earlier than the scheduled date of delivery (for example, at 33–34 weeks). Operative delivery is also used in the following cases:

1. The woman is carrying triplets.
2. The position of one of the fruits is incorrect.
3. One of the fruits is large.
4. One of the babies has signs of hypoxia.
5. Generic weakness observed during past births.
6. Previous births were by caesarean section.

With multiple pregnancies, a caesarean section is much more often prescribed for a woman.

With natural (vaginal) delivery, the process is often associated with complications. For example, in the first period, approximately 30% of women in labor experience premature rupture of amniotic fluid. Moreover, it can be accompanied by prolapse of the umbilical cord. Since the uterus is overstretched, contractions are often weak: as a result, the opening of the cervix is ​​greatly delayed.

The period of expulsion of the first fetus is often long (weak attempts due to overstretching of the muscles of the abdominal wall). In this case, a woman is given a dropper with oxytocin (in this case, pain relief should be minimal). The presenting part of the second child tends to get into the birth canal at the same time as the first, which additionally increases the time. Prolonged labor is fraught with infection of the uterine cavity and the occurrence of child hypoxia.

During childbirth, the doctor monitors the work of the heart of both children. After the birth of the first baby, the condition of the second is monitored.

Another scenario is a rapid birth due to prematurity of the fetus. In this case, there is a high probability of rupture of the perineum.

Another complication is premature detachment of the placenta. It occurs after the birth of the first baby: inside the uterus, the pressure decreases sharply and the volume of the organ decreases. As a result, severe bleeding occurs with the development of hypoxia in the fetus. To prevent such an outcome of events, doctors urgently pierce the remaining fetal bladder (another baby should appear no later than 15 minutes later).

In addition, after the birth of the first child, the umbilical cord is tied not only from the side of the fetus, but also from the maternal end. After all, if the twins are identical, then the other baby may suffer due to bleeding from the vessel.

The period of expulsion of the placenta also poses an increased danger with multiple pregnancy, since after it there is a high probability of bleeding. In this regard, a woman is injected with uterotonic drugs (increasing the tone of the uterus) within two hours after childbirth. In addition, doctors carefully examine the placenta to ensure its integrity. Sometimes, again, because of the overstretched uterus, the placenta comes out with difficulty, so a drip of oxytocin is required. If there is no effect, then the placenta is separated manually.

The postpartum period after the birth of twins is often fraught with complications. This is, first of all, delayed recovery of the uterus and postpartum endometritis. To prevent these conditions, a woman is prescribed funds to reduce the muscles of the organ and anti-inflammatory drugs.

Video: natural childbirth or caesarean with twins? (doctor explains)

Risk factors for fetuses

A multiple pregnancy is not only difficult for the mother’s body (the likelihood of all kinds of complications doubles), but also carries quite large risks for babies:

1. Twice as often, malformations are recorded.
2. Delay in the development of one of the fetuses is recorded more often 10 times. If twins are dichorial, then this is 20% of children, if monochorionic - 30%. In general, the delay in the development of twins is 1.7% and 7.5%, respectively.
3. Cerebral palsy develops 3-7 times more often in a child from a domestic breeder, and 10 times more often from a triplets.
4. Intrauterine mortality occurs more often by 3–4 times.

The probability of occurrence of fetal structural anomalies is high if the twins are monozygotic (the risk increases by 2-3 times). If the twins are fraternal, then the probability is the same compared to a singleton pregnancy.

The main danger in carrying twins are disorders in the circulatory system between the fetus and the placenta. Due to asymmetric blood circulation in the placenta (identical twins), blood flow to one of the fetuses may decrease (5–25% of cases). As a result, he receives less nutrition: he suffers from hypoxia, lags behind in development, has a much lower weight, and may even die. In another, at this time, hypertension, enlargement of the heart, etc. is observed from excess blood. In addition, there are cases of connection between large vessels, as a result of which blood from the artery of one child can enter the vein of another.

Due to uneven blood circulation or abnormal connection of blood vessels, one of the fetuses may receive less nutrition, lagging behind in development