Physiological pregnancy and accompanying changes in the body

Norms for pregnancy duration

If the expectant mother knows the date of her last period, she can calculate when her baby will be born approximately before registering with the antenatal clinic. But often the calculations of the woman and the gynecologist do not coincide. Why?

The fact is that there are 2 terms:

1. Obstetric. Gynecologists focus only on him. The duration of pregnancy is calculated based on the last menstrual period before conception. And it is this that is taken into account during pregnancy, ultrasound, tests, and measurements of the child’s parameters. As a rule, women remember when they had their periods, so this calculation is more accurate;
2. Embryonic. This period is 2 weeks behind the obstetric period. The fact is that when calculating it, the date of the last menstruation is not taken into account. The countdown begins from conception.

The average duration of pregnancy in the embryonic period is 38 weeks, and in the obstetric period - 40 weeks. Childbirth can begin 2 weeks earlier or later, that is, at 38 - 42 weeks. This is considered the normal limit.

Physiological pregnancy and accompanying changes in the body

Pregnancy

is a physiological process of development in the female body of a fertilized egg, beginning from the moment of fertilization of an egg matured in the ovary (female reproductive cell) by a sperm (male reproductive cell).

Physiological pregnancy lasts on average 10 lunar months (1 lunar month – 28 days), i.e. 40 weeks or 280 days. The entire pregnancy period is usually divided into trimesters. The 1st trimester begins with fertilization and ends at 12-13 weeks, the second ends at 28 weeks, and from the same period begins the third trimester of pregnancy, ending with childbirth.

Fertilization usually occurs in the ampullary portion of the fallopian tube facing the ovary. Thanks to the rhythmic contractions of the fallopian tubes, the fertilized egg moves into the uterine cavity. During this movement along the fallopian tube, the egg turns into a multicellular embryo (fertilized egg), densely covered with delicate villi - with their help it attaches to the mucous membrane lining the inner surface of the uterus. From the moment of attachment to the mucous membrane of the uterus, the formation of first the embryo, then the fetus begins, accompanied by a restructuring of all functions and systems of the woman’s body. At the site of attachment of the embryo, the villi grow luxuriantly and form the so-called baby's place or placenta, connected to the fetus through the umbilical cord. Through the placenta, nutrients and oxygen are supplied to the fetus from the mother through the blood vessels of the umbilical cord, and metabolic products are removed. Functional changes in the body of a pregnant woman are essentially adaptive reactions that provide favorable conditions for the development of the fetus.

Diagnosis of early pregnancy.

The possibility of pregnancy can and should be assumed in any woman of childbearing age who has not had her period on time or who has amenorrhea (absence of menstruation) during regular sexual activity.
Thus, the first sign of pregnancy is usually the absence of menstruation at the scheduled time
.
A few days after the onset of menstruation, most women experience nausea and even vomiting. Vomiting usually occurs once or twice a day, in the morning, immediately after getting out of bed, but it is not so severe as to cause noticeable metabolic disturbances. Increased urination
is also common in non-pregnant women during the premenstrual phase.
However, in pregnant women it is more noticeable and can give the first indication that conception has occurred. Changes in the mammary glands
are also noted from the very beginning of pregnancy and are especially noticeable in women who are pregnant for the first time.
Usually a woman feels some stretching of the mammary glands and their soreness. The swollen mouths of the areola glands around the nipple can protrude upward, forming the so-called Montgomery tubercles. With sufficient lighting, the swelling of the superficial veins, especially those around the nipple, becomes visible. The breast loses its usual softness and strands of swollen glandular ducts can be felt in it, running from the periphery to the nipple like spokes in a wheel. After 14 weeks, nipple discharge appears, progressing as pregnancy progresses, and the mammary glands noticeably increase in size. After 16 weeks, pigmentation of the nipple
, especially pronounced in dark-skinned women.

From about 12 weeks, and in thin women a little earlier, you can feel the fundus of the uterus through the anterior abdominal wall, which at 20 weeks approaches the lower edge of the navel, and at 36 - to the xiphoid process of the sternum.

Multipregnant women notice fetal movements earlier

than first-time pregnant women. The former usually notice movements between 16 and 18 weeks, and the latter between 19 and 21. Data about these sensations can be very important for determining the duration of pregnancy and the upcoming birth, so the woman should try to more accurately remember the date of the appearance of fetal movements.

There are also special methods for diagnosing pregnancy. In doubtful cases, a woman can determine the onset of pregnancy using express pregnancy tests

, sold in pharmacies or by conducting an immunological test in a antenatal clinic to determine the hormone - human chorionic gonadotropin.
Modern diagnostic ultrasound devices make it possible to establish pregnancy at a minimum period of 2-3 weeks.
The accuracy of diagnosis increases with dynamic observation and transvaginal scanning (when a special sensor is inserted into the vaginal lumen and the examination is carried out as if from the inside).

Every pregnant woman must register with the antenatal clinic

and the sooner the better. After all, in the early stages of pregnancy, she still remembers exactly the days of her last menstruation, and the accuracy of the information can be checked during a bimanual examination performed by a gynecologist. In addition, during this period, the doctor needs to obtain initial data on pulse rate, blood pressure, blood hemoglobin level, body weight, so that if they change at a later date, he can quickly assess the situation and, if necessary, take the necessary measures without delay . It is during this period that the doctor needs to identify concomitant diseases of the internal organs, such as hypertension or heart disease, peptic ulcer disease or diabetes mellitus, which ultimately can have a significant impact on the condition of the expectant mother and her child and modify the management of the pregnant woman accordingly.

In addition, the primary medical examination includes determination of blood group, Rh factor, as well as serological tests for syphilis and HIV infection.

If the woman is 35 years or older

, that is, the risk of chromosomal abnormalities that can lead to the development of various fetal malformations and diseases (the most common is Down's disease). In these cases, the doctor will recommend undergoing a special examination - amniocentesis (a thin needle is used to puncture the wall of the uterus and amniotic sac, and the resulting amniotic fluid is analyzed). In addition, women undergo ultrasound examination (ultrasound), which is acceptable at any time (its harmlessness has been confirmed by numerous studies conducted for more than 30 years all over the world).

In general, pregnancy can be considered as a process of long-term physical adaptation of the mother’s body, necessary to meet the needs of the growing fetus and ensure the constancy of the internal environment in which its growth occurs. The degree of this adaptation generally exceeds the needs of the fetus, so there are significant reserves to endure periods of stress or deprivation without significant changes in the fetal environment. Each of the systems of a woman’s body undergoes serious changes and tests. For example, by 34 weeks of pregnancy

the amount of circulating blood increases by 30-40% and then decreases slightly. The level of blood proteins decreases from 7 to 6 g/l, which causes a drop in plasma osmotic pressure, due to which pregnant women are prone to edema. The total number of leukocytes (white blood cells) increases slightly, but the ESR (erythrocyte sedimentation rate) in pregnant women increases sharply and can reach 50 mm/hour. The platelet count approximately doubles. The lipid content in the blood increases from 6 to 9 g/l, mainly due to cholesterol.

Mean arterial pressure, apart from a tendency to drop slightly in mid-pregnancy, increases slightly, which facilitates the transfer of oxygen from mother to fetus. Oxygen consumption increases. Speaking about changes in the vascular system, we note that pregnant women experience dilation of skin vessels, as a result of which the woman feels the cold less and can sometimes feel worse in hot weather. The increase in superficial blood flow is more noticeable on the ulnar side of the palms as palmar erythema (redness).

As pregnancy progresses, the movement of the diaphragm is significantly limited and breathing becomes more thoracic in nature. The volume of respiratory air increases, which reduces the pressure of carbon dioxide and thus facilitates the excretion of carbon dioxide through the placenta. By the time of birth, oxygen consumption increases from 10 to cm3. in a minute.

In the first and second trimesters of pregnancy

renal blood flow increases, gradually returning to its original level at the time of delivery. The rate of renal filtration (urine production) increases by 50%, returning to normal only after childbirth. The excretion of urea and uric acid also increases. At approximately 16-20 weeks of pregnancy, the renal threshold for filtering glucose drops sharply, which is why glucosuria (sugar in the urine) occurs quite often in pregnant women.

The weight gain of a pregnant woman varies widely from person to person, but on average a woman gains 12 kg during pregnancy.

. One third of the gain, 4 kg, is gained in the first half of pregnancy, and the remaining 2/3 (8 kg) in the second. 60% of the total body weight gain is due to fluid retention, which in turn is caused by the accumulation of sodium (about 20 g) due to increased secretion of the hormone aldosterone. The retained water is distributed as follows: in the blood plasma 1.3 l; in the fetus, placenta and amniotic fluid – 2 l; in the uterus and mammary glands - 0.7 l and in extragenital interstitial fluid - 2.5 l. At the time of birth, the fetus, placenta and amniotic fluid together weigh about 5.5 kg. And this mass is lost after childbirth. The remaining 6.5 kg is due to the uterus, breast enlargement, extragenital fluid retention (increased blood volume, edematous fluid, etc.) and fat reserves, especially in the thighs and buttocks. After a sharp decrease in body weight in the first four days after birth due to increased diuresis resulting from the cessation of placental hormones, it continues to gradually decrease over the next 3 months or so.

Pregnant women also experience increased skin pigmentation

, especially pronounced on the face, around the nipples and the white line of the abdomen (brighter in brunettes compared to blondes). This phenomenon is caused by an increase in the amount of circulating melanocyte-stimulating hormone. Longitudinal stripes (striae of pregnancy) 5-6 cm long and about 0.5 cm wide appear on the stomach and thighs. At first they are pink, but then they become pale and slightly denser.

Birthmarks appear in more than 50% of pregnant women. The intensity of the sebaceous and sweat glands during pregnancy increases.

To summarize, we can say that during the gestational period, profound shifts in physiological functions occur, aimed at meeting the needs of the developing fetus and compensating for the physical changes in the mother’s body that are caused by these shifts. At each stage of pregnancy, physiological changes are aimed at meeting the needs of the fetus and providing such reserves that allow it to grow and develop continuously.

Although it is rightly believed that pregnancy is a physiological state of the body and many women are ready for a harmonious relationship with their unborn child, it is known that pregnancy is also a period of tension and stress and that in few women it occurs without functional or organic disorders of varying degrees of severity.

Make an appointment with specialists by calling a single call center:

+7(495)636-29-46 (metro stations “Schukinskaya” and “Street 1905 Goda”). You can also make an appointment with a doctor on our website, we will call you back!

What determines the duration of pregnancy

There are a number of factors that influence the duration of gestation.

The first factor is the woman’s health. Women with a healthy reproductive system and body as a whole, who have not previously had abortions, miscarriages or other pregnancy pathologies, have every chance of giving birth to a full-term baby. If a pregnant woman has chronic diseases or gets sick while pregnant (for example, an infection), this may affect the duration of pregnancy.

The second factor is age. Young girls often give birth to children earlier, and mothers between the ages of 30 and 35 more often carry their pregnancy to term.

The third factor is the number of births in the past. Women who have already given birth give birth earlier than those who enter the delivery room for the first time.

The fourth factor is the course of pregnancy. This includes any deviations from the norm: placenta previa and placental abruption, early ripening of the cervix, gestosis and other conditions of the expectant mother that require early delivery.

The fifth factor is socio-psychological. Pregnant women who are nervous, lead an unhealthy lifestyle, work in hazardous industries, live in constant stress or an unfavorable environment, eat poorly, risk giving birth to their baby at the wrong time.

The sixth factor is the condition of the fetus. Body weight, hormonal status, bone density - all this affects the duration of pregnancy and the readiness of the baby to be born.

The influence of the placenta on the duration of pregnancy

The placenta plays a huge role in the course and duration of pregnancy. Through it, oxygen and nutrients are supplied to the baby; it acts as the baby’s excretory system.

Scientists from Durham University conducted a study that compared the placenta of mammals from different species. They came to the conclusion: the placenta, connecting mother and fetus, affects the duration of pregnancy. And it depends on the structure of the placenta itself: the more complex it is, the faster the gestation period ends. In women, it has a simple structure, and fewer nutrients pass through it for the fetus - which is why the intrauterine development of human children takes as long as 9 months. If the condition of the placenta is not normal, then the duration of pregnancy can be sharply reduced or, conversely, increased.

Causes

Here we rather have to talk about risk factors for the development of delayed labor.

Let's consider these risks from the mother's body and from the baby.

Risk factors from the maternal body:

• disorders in the reproductive health of a pregnant woman. Such disorders may be inflammatory diseases of the reproductive system, leading to endocrine disorders and changes in the neuromuscular system of the uterus, a history of abortion, maternal infantilism, irregular menstrual cycle;
• the age of a woman preparing for motherhood for the first time is over 35 years old;
• maternal pathologies associated with pregnancy. These may be metabolic diseases, endocrine pathology, pathology of internal organs, gestosis and toxicosis, mental shock;
• sedentary lifestyle during pregnancy, especially in its final stages;
• hereditary predisposition. There is often a pattern of repeated cases of post-term pregnancy in families where close relatives have already had late births.

Possible causes from the fetus:

• Often, the reasons that cause slow development of the fetus lead to an extension of the gestational age. In this case, such a phenomenon as prolongation of pregnancy can be considered an adaptive mechanism that contributes to the ripening of the fetus;
• a large fetus weighing over 4000 g. A large baby often cannot descend to the entrance to the pelvis. This interferes with the proper opening and preparation of the uterine os for childbirth;
• for the same reason - the inability to descend into the small pelvis - the transverse or pelvic presentation of the child also contributes to an increase in pregnancy;
• the baby’s immature immune system due to lack of nutrients.

What is premature birth

In 5 - 12% of cases, babies are born prematurely - at 22 - 37 weeks and weigh 1 - 2.5 kg. Previously, birth was considered premature from the 28th week, and everything that happened before it was considered a miscarriage. It was impossible to go out and save such babies.

But medicine does not stand still; new methods of caring for premature babies are being introduced in obstetrics. Therefore, the World Health Organization has expanded the scope: now babies born from the 22nd week have a chance to live. In modern perinatal centers, babies are cared for with extremely low body weight - only 0.5 kg.

How is the term calculated?

There are obstetric (gestational) and ovulatory (fertilization) stages of pregnancy. The first is complete, less accurate and easier to calculate. The second is factual, the most accurate, but it is more difficult to calculate.

Doctors have calculated the menstrual cycle that is typical for the majority of women who do not have any abnormalities.
It consists of 28 days with ovulation on the 14th day - the middle of the cycle.
Ovulation is the release of an egg from the ovary. After leaving the ovary, the egg is fertilized or not fertilized in the fallopian tube.

An unfertilized egg is released from the body during menstruation. If the egg is fertilized, after ovulation it will travel to the uterus and become implanted in it.

Since in practice, calculate the exact date of fertilization

difficult, in addition, it can be changed by the current emotional and physical state of the woman, the activity of sperm, it is customary to take into account all the days after the onset of the last menstruation as days of probable pregnancy.

In practice, there have been cases when a couple neglected protective measures the day before menstruation, hoping that pregnancy would not occur and everything would go away with menstruation. As a result, the next scheduled periods passed, but the next ones did not occur.

Doctors usually calculate the duration of pregnancy in women in weeks, not months. How to calculate how many obstetric weeks a pregnancy lasts?

When registering for pregnancy, the gynecologist determines the obstetric gestational age

: the date of the start of the last menstruation is found out, and weeks are counted from it until the meeting with the doctor. This will give you the current date, but it is not completely accurate. In fact, on the day of the onset of menstruation, a woman cannot be pregnant, but instead of trying to calculate the actual day of fertilization, which is extremely difficult, it is customary to take into account the last date of probable fertilization.

The ovulation period is counted from the day of ovulation. Take a calendar with marked start days of menstruation for the last six months. It is generally accepted that ovulation occurs 14 days before the onset of menstruation or between the 13th and 15th day of the menstrual cycle. Using the marks on the calendar for at least 6 months, you need to check the regularity of menstruation and calculate your ovulation day. Count the weeks from the date of the last ovulation, and here it is - the ovulation period.

Later, the period is confirmed or refuted at the first screening at 11-12 obstetric weeks

. At this stage of development, the fetus has certain external features that are characteristic of a specific stage of pregnancy. Ultrasound clearly shows the state of development of the embryo and makes it possible to set a more accurate date.

Types of early birth

A distinction is made between impending and incipient labor.

Threatened labor can be brought under control and true labor can be prevented. With proper therapy, a woman can carry to term and give birth on time. They can be suspected if they have the following symptoms: nagging pain in the lower back and lower abdomen, traces of blood on the pad, the fetus may be more active than usual. In such a situation, you need to urgently call an ambulance.

The onset of labor cannot be controlled - in this case there is no turning back. The cervix dilates by 4 cm or more, regular contractions appear - starting with an interval of 10 minutes, which are reduced, the fetus moves along the birth canal. In this case, the obstetrician’s task is to competently conduct the birth and deliver the child.

Examinations that can confirm that the gestational age has been exceeded

Diagnosis of post-term pregnancy is difficult, since the clinical manifestations of this pathology are erased.

First, the gestational age is recalculated again and the expected date of birth of the baby is checked. Risk factors for postmaturity are determined. A more thorough obstetric examination is then carried out.

Methods for determining deadlines and dates have already been discussed above. Let's move straight to the obstetric examination.

Examination data in favor of post-term pregnancy:

• weight loss of the expectant mother by 800-1000 g per week (sometimes more) after 41 weeks, together with the appearance of signs of decreased skin elasticity;
• reduction in abdominal circumference by 5-10 cm after the 290th day of pregnancy;
• the height of the fundus of the uterus stops growing or decreases;
• fetal mobility decreases due to oligohydramnios. A woman feels movements less often. Moreover, these movements are not intense, but sluggish, “lazy”;

A vaginal examination can determine that:

• the cervix is ​​not prepared for childbirth (the cervix is ​​long, not elastic, the cervical canal is tightly closed);
• The bones of the baby’s head are dense, bone sutures and fontanelles cannot be felt.

Obstetricians and gynecologists regularly listen to the baby's heart sounds with an obstetric stethoscope. When postmaturity occurs, the nature of the baby's heart sounds changes - their sonority, heart rate, and rhythm change. However, these changes are not specific to postmaturity, but to a greater extent indicate oxygen starvation of the baby.

A gynecologist observing pregnancy, after conducting the above examination at forty weeks of pregnancy, recommends hospitalization in a maternity hospital. The purpose of hospitalization is to clarify the obstetric status of the expectant mother and the condition of the baby. A specialized hospital has greater opportunities for detailed, in-depth examination of expectant mothers, so there is no need to be afraid or avoid hospitalization.

Helpful: Fetal movement during pregnancy

Instrumental methods of examining a pregnant woman in a hospital are used to determine the functional state of the fetoplacental system, to determine further tactics for managing the pregnant woman and to select the method of delivery in this particular case.

Fetal cardiotocography

Fetal cardiotocography (CTG) can detect changes in the state of the fetal cardiovascular system. Mainly, this method allows you to determine the presence of oxygen starvation of the baby (hypoxia). Indicators such as the lack of reactivity of the baby’s cardiovascular system to his movements (non-stress test) or uterine contractions (stress test), although not specific for a prolonged pregnancy, but indicate that the fetus is not all right.

They manifest themselves as monotony of the heart rhythm, increased heart rate of more than 150 beats per minute or a decrease in their frequency of less than 110 beats per minute. If such changes are detected, wait-and-see tactics are not used; urgent actions must be taken to save the child.

Reasons for preterm birth

Factors that influence the duration of pregnancy and the birth of a baby early can be divided into 2 groups.

The first is socio-biological factors. These include:

• bad habits during pregnancy - alcohol, nicotine, drugs, as well as taking medications that harm the fetus;
• unhealthy lifestyle - poor or unhealthy diet, passive lifestyle, weight problems (excess or deficiency);
• difficult working conditions - for example, night shifts, physical labor, hazardous work conditions (vibrations, noise, toxic substances);
• emotional state - stress, anxiety, excitability or depression, dysfunctional social environment or family atmosphere affect the duration of pregnancy.

Women who lead an unhealthy lifestyle or do not take care of themselves during pregnancy often give birth to premature babies.

The second group is medical factors. These include chronic diseases, previous abortions and miscarriages.

Another reason is pregnancy complications. For example, gestosis in the third trimester, Rh conflict between mother and fetus, or disruptions in a woman’s immune system when her body perceives the fetus as foreign and tries to expel it.

Other medical factors also affect the length of pregnancy. Let's talk about them in more detail next.

Infectious diseases in women

Some infections can cross the placental barrier and affect the fetus. Infection of the fetus leads to developmental disorders, health problems after birth and premature birth.

Such ailments include sexually transmitted infections, as well as inflammatory processes in the genitourinary system, kidneys or lungs. At risk are women diagnosed with chlamydia, herpes, gonorrhea, and trichomoniasis.

Isthmic-cervical insufficiency

If the cervix ripens faster, it opens earlier and therefore cannot hold the fetus. This shortens the duration of pregnancy.

Early outpouring of water

When your water breaks, prostaglandins are released. These hormones trigger the labor mechanism.

Anatomical features of a pregnant woman

Some women have a different uterine structure than most. In such cases, the duration of pregnancy may be less than normal.

Pathologies of pregnancy

These include placenta previa or placental abruption, for example. In the first case, the woman is usually kept in a maternity hospital, since she may experience massive bleeding at any moment. When placental abruption occurs, the same thing happens, so the woman needs emergency medical care.

Placental abruption itself is not a sign of labor. It’s just that if it occurs in the later stages, then doctors save not only the life of the woman in labor, but also the child.

Predictions for children

If a baby was born from the 22nd to the 28th week, he has a chance to survive, but the prognosis is not the most favorable: health complications cannot be avoided. Babies born from the 28th to the 33rd week have a slightly more positive outlook: their lungs mature faster and better thanks to drug therapy. Well, the best chances are for babies born from the 34th to the 37th week.

Causes and consequences of deviations from the norm in pregnancy duration

Although deviations from the obstetric term up or down by no more than 1–2 weeks are normal, a large difference can lead to complications during childbirth and the postpartum period. Premature birth is considered to occur between 22 and 37 weeks of pregnancy, and if the baby weighs more than 500 grams. Late birth is one that occurs at 41–42 weeks of gestation.

Table: causes and consequences of premature or post-term pregnancy

When 2 years ago my son and I were referred to a neurologist with suspected attention deficit hyperactivity disorder (ADHD), the doctor immediately assumed that the little one was born prematurely. Having heard an affirmative answer, he said that ADHD is more common in premature babies, and sometimes without making itself felt for many years. The trigger can be a stressful situation, as in our case. Living in a war zone, his six-year-old son witnessed a Smerch missile hit the ground near their kindergarten. Fortunately, we noticed the alarming symptoms in time and sought medical help. It was possible to avoid strong medications, which are often prescribed to children with ADHD. If in the first grade there were frequent complaints about his behavior, then in the second the number of comments noticeably decreased. So, if your children were born prematurely, be more attentive to them not only in the first 3 years, but also after this age.

Signs of post-term pregnancy

It is diagnosed based on an assessment of the condition of the mother and fetus.

From my mother's side. The woman’s body is not ready for labor, the abdominal circumference has become smaller, the height of the uterus has increased, aging of the placenta and fetoplacental insufficiency are noted, the amniotic fluid has become cloudy, mixed with meconium.

From the side of the fetus. The bones of the skull have become denser, the fontanels, sutures and subcutaneous fat layer have decreased, there is no vellus hair or cheese-like lubricant. The weight of the fetus exceeds 4 kg, it grows by 2 - 3 cm. Such a baby may experience heart rhythm disturbances: arrhythmia, extrasystole.

Another criterion is labor activity. It may start, continue for 24 hours, and then stop and not return for a week.

If the duration of pregnancy exceeds 42 weeks, the woman is examined in the maternity hospital. If, when assessing the condition of the fetus, it is revealed that it is suffering in utero, then labor is induced or a caesarean section is performed.

What rules must be followed to give birth at the right time?

If for any reason you are in the risk group of women with a risk of premature birth or post-term pregnancy, your doctor should definitely draw up an individual prevention plan for you. It depends on the reasons that provoke possible deviations from the normal duration of pregnancy. General recommendations for pregnant women to ensure that they give birth on time include the following:

• answer all questions truthfully when registering so that the deadline is set as accurately as possible;
• do not miss visits to the doctor, undergo the necessary examinations and tests on time;
• carry out all doctor’s prescriptions for the treatment of identified pathologies, it is advisable to do this at the planning stage;
• if the doctor insists on hospitalization, agree;
• report the slightest ailments and short-term symptoms;
• get rid of bad habits;
• Avoid crowded places, especially during epidemics of infectious diseases.

After 38 weeks of pregnancy, the baby’s intrauterine development can be considered complete, the baby is ready to be born.
The threat of premature birth requires therapy that will prolong gestation as long as possible. Especially if the baby risks being born before the 28th week, because its organs and systems are not yet ready for independent life outside the mother’s womb. If the pregnancy is postterm, labor can be stimulated as early as 41 weeks. The decision is made by the obstetrician based on the results of intrauterine examinations (ultrasound, analysis of amniotic fluid), showing the pathological condition of the fetus.

Video: is it possible to know exactly when a baby is born?

Why is the baby born later?

Doctors name several reasons why waiting for a baby may take longer.

Firstly, the age of the woman in labor. Mothers over 30 tend to carry their pregnancies to term.

Secondly, disruptions of the menstrual cycle. For example, if a woman incorrectly named the date of her last menstrual period or does not remember it at all, then an error in calculating the PDR is quite possible.

Thirdly, diseases. Inflammatory processes in the genitourinary system can both cause premature birth and delay the birth of the baby. Therefore, pregnant women with chronic illnesses need to be doubly careful to avoid exacerbation.

Fourthly, the characteristics of the mother’s body. Infantilism of the genital organs, absence of a generic dominant, endocrine system disorders, hormonal insufficiency of the placenta. Another reason is the characteristics of the central nervous system. The same mothers often carry their pregnancies to term.

Fifthly, the condition of the fetus. Children with disorders of the pituitary-adrenal system or defects are born later.

Predictions for the baby

The birth of post-term babies is fraught with injury, since their skull bones are denser and compress less well during the passage of the birth canal. Therefore, such newborns are at risk for traumatic brain injury.

Another complication is hypoxia. During birth, babies experience oxygen starvation. But those born at 40 weeks tolerate it more easily than those born at 42 and later. The latter have a more complex nervous system, so it is more difficult for them to adapt to oxygen deficiency.

Post-term infants are at risk for perinatal diseases and mortality.

Wang Shi - pregnant record holder from China

In 2021, a girl from a Chinese province entered the Guinness Book of Records for having the longest pregnancy period. Wang Shi was in the position for 17 long months. The whole world learned about her, newspapers wrote in her homeland, in England and the USA. Wang Shi became pregnant in February 2015, after an ultrasound examination, experts reported that the baby was due on November 15. Everything did not go according to the gynecologists’ plan; the child was not born, continuing to sit in the womb for a long time.

The Chinese woman was worried, began to constantly visit the clinic, ask doctors for help, and underwent frequent examinations. The gynecologists concluded that the child had not developed enough and it was impossible to resort to a caesarean section, although the term was 14 months. Husband Wang Shi said that gynecologists reassured them, assuring them that this is normal; in the world they often give birth after a long period of 13 months. They had to wait until the newborn decided to come into the world on his own; the doctors did not explain to the spouses why this was happening. The Chinese woman did not complain about her health; after the next examination, doctors set a day for surgery, when the period was 18 months. On August 18, a caesarean section was performed, and a healthy baby weighing 3,800 kg was born.

Wang Shi was not at all pleased with such popularity; the Chinese woman admits that it was a shame to be pregnant for such a long time. The family spent a lot of money on checks and tests - about 10,000 yuan, or 1,500 US dollars. The woman's weight increased by 26 kg during pregnancy. Wang weighed 52.2 kg at the beginning of pregnancy, 78 kg before giving birth.

In China, Wang's pregnancy was discussed very actively for a long time; not all doctors believed the Chinese woman, accusing her of lying and trying to get into the Book of Records. A doctor from the hospital said that the woman’s card did not contain any tests, although she and her husband claim that they spent a lot of money on examinations in clinics. Most likely, the cause of the longest pregnancy was placenta previa. This is a rather serious problem that occurs in every 200th pregnant woman in the world. The cervix is ​​completely or partially closed.

How long to carry

The duration of pregnancy ranges from 38 to 42 weeks. Fluctuations depend on the estimated date of pregnancy (the day of fertilization or the day of the start of menstruation) and the individual characteristics of the woman.

It has been proven that for a fetus to fully develop, it needs to spend
266 days in the womb.
This is exactly 38 weeks . At this stage, the child is considered fully formed and capable of life in the external environment.

How many obstetric weeks does pregnancy last? To the standard 38 weeks, add 2 weeks of “theoretical” pregnancy and get 40 weeks.

This is the standard length of pregnancy according to obstetric calculations. Thus, the full pregnancy cycle is 40 weeks.

If you calculate in months, then how many months is it? Obstetric months differ from real (calendar) months. They have strictly 28 days, which corresponds to the lunar calendar. If we take obstetric months as a basis, then the duration of pregnancy, recalculated from 38 weeks, is equal to nine and a half months

, and 40 weeks is 10 months.

Note!

After 16 weeks, ultrasound is not able to determine the actual period, since the stages of development of the embryo end, it becomes similar to a person and subsequently increases in size without changing in appearance.

Delayed ovulation is not new for a long time, so a normal pregnancy occurs within 38-42 weeks.