How many weeks does the pregnancy last and what does it depend on?

Women who are preparing to become mothers are always interested in how much pregnancy is going on and what factors may influence this. The length of the term of carrying a baby is quite individual and depends on many reasons.

For the formation and maturation of the baby in the mother's womb, nature has set aside quite a definite time - to this it takes from 266 to 280 days. It is generally accepted in the people that pregnancy lasts for nine months, but in practice everything is a little different. Normal pregnancy lasts from 37 to 42 obstetric weeksthere is no difference if a woman is pregnant with a girl or a boy - children of both sexes go through the same stages of formation and growth in the prenatal period of their development.

Obstetricians measure time differently - they use not the usual calendar, but weeks for 7 days. Thus, one obstetric month is exactly 4 weeks, while a calendar month can consist of 30, 31, or 28–29 days. Obstetricians start counting not from the moment of conception of the baby, since in most cases it is impossible to establish this moment, but from the first day of the last menstruation. Therefore obstetric period is always 14 days ahead of embryonic.

It would be pointless to consider ovulation - ovulation in all women occurs at different times., errors are possible for several days, because the menstrual cycle proceeds differently. The exact date of sexual contact, which led to the birth of a new life, is known not by all women, because for an adult healthy woman it is quite normal to have a regular sex life. But by default, it is assumed that a child can be conceived only during the ovulation period and during the day after it, while the egg cell is viable. However, the moment of ovulation itself is not obvious. The most averaged and accurate method is the method of counting from the first day of the last menstruation, usually women remember him.

This question in women is one of the most painful. At first glance, it is rather difficult to answer what exactly the deadlines can move in one direction or another, but influence factors still exist. Let's look at them in more detail.

• Heredity. Many people underestimate the genetic factor, whereas this is very important. If women in the family in a direct ascending line (mother, grandmother, great-grandmother, etc.) had a premature birth or there were cases of recurring, then most likely the pregnancy will continue for less than 38 weeks or more than 42 weeks. The probability increases if the tendency to late delivery was observed in two or more women in the ascending genetic line.
• Age. Future mothers who are not yet 20 years old, as well as women older than 36 years old, are more likely to have premature or late births.
• Number of births. If the birth first, there is usually a tendency to perenashivaniya, increase the term. If there were a lot of births, then there is a chance not to deliver the baby before 38 weeks, since the woman’s body goes through all the stages of prenatal preparation.
• Maternal health. If any chronic diseases are present in a woman, even if they are not related to the reproductive organs, the risk of giving birth to the baby is too high.

• Lifestyle features. Women who are in an "interesting position" can not part with a cigarette or a glass of wine, more than others risk giving birth to premature. Almost the same risks exist for women who are in a state of chronic stress, are experiencing, are nervous, are in an unfavorable psychological environment. Sedentary ladies, who spend most of their time on the sofa by the TV, have every chance to change their pregnancy.
• Psychological factor. We should not ignore the psychological reasons that affect the childbearing in most cases, although they are not given due importance by obstetricians. For example, the fear of a generic pain or of the fact that it will be difficult to cope with a child provokes muscle clamps in women, the cervix is ​​not ready, it matures longer, which leads to pererashivaniyu up to 42 weeks or more. Severe chronic stress, which does not find a way out, can be a provoking factor in the contraction of the uterine muscles, which will lead to premature birth.
• Multiple fetus. If a woman has double or triple joy because of carrying two or three babies in the womb, she should prepare for the birth to be earlier than that of other pregnant women who bear one child - two babies put more pressure on the internal cervix of the cervix, and therefore The birth process usually begins before the 38th week of pregnancy.
• Features of the female cycle. Remember how many days your menstrual cycle lasts. If it is usually short and lasts less than 28 days, then there is a high probability of giving birth ahead of time. Women with a long cycle - from 35 days or more, usually give birth after 40–41 weeks, or they reposition even longer.

Premature births are considered to occur between the 22nd and 37th week of gestation. You should not focus on the notorious 40 weeks, since a deviation from this date for a couple of weeks in any direction is not a pathology, childbirth from week 37 to week 42 will be considered urgent, that is, occurring on time. No matter how hard doctors and scientists try, they haven’t succeeded in finding out a single mechanism for the development of childbirth ahead of time. That is, it is not clear what the generic activity of the female body starts when neither the baby nor the mother is ready for it: there is no necessary level of certain hormones, there is no proper maturation of the baby’s lung tissue, etc.

However, there are sufficiently studied risk factors that increase the likelihood of giving birth to a baby before the appointed time. They are conventionally divided into maternal, gestational and socio-biological.

• Maternal factors - burdened obstetric history: several abortions in a woman’s personal medical history, operations on the uterus, ovaries, the presence of several miscarriages and premature births that have already taken place earlier.
• Gestational factors - lack of water and high water in the current pregnancy, functional failure of the cervix (isthmic-cervical insufficiency), tumors of the reproductive organs, placenta previa, sexually transmitted infections (chlamydia, ureaplasmosis) suffered during infection (chickenpox, rubella, measles); diseases of the heart, blood vessels, kidneys, diabetes mellitus and hypertension. This also includes genetic pathologies and malformations of the fetus, pronounced Rh-conflict of the Rh-positive child with the Rh-negative mother, abnormal fetal presentation.
• Socio-biological factors - inadequate living conditions, poor nutrition and vitamin deficiencies, alcohol and drug use, and being in a state of chronic stress.

Consequences of preterm birth directly depend on how long the baby was born. The closer to week 37, the higher the likelihood of a favorable outcome without complications. The earlier a child appears, the higher the probability of his death or disability.

The three main threats in this case are:

• the immaturity of the lung tissue due to the small amount of accumulated surfactant - as a result, acute respiratory failure may develop;
• low amount of subcutaneous fat in a child - as a result of low or extremely low weight and the inability to retain heat of your own body, system hypothermia;
• the immaturity of the internal organs, their unwillingness to work independently in the changed conditions, the immaturity of the central nervous system is especially dangerous, which can cause paralysis, blindness, and deafness.

Modern medicine has gone a long way in the rescue of premature babies. Previously, a child with a weight of less than 500 grams was not even tried to save, they considered it a miscarriage. Today from different points of the country from time to time there are reports that they managed to save children weighing 450 and even 420 grams.

Resuscitation care is at a high level, and therefore most of premature babies can still be saved, but unfortunately, no one can guarantee the consequences that may exist in terms of their health. All this suggests the need for prevention of preterm birth - A woman should be very attentive to her well-being and follow all the recommendations of the doctor.

If the deadline specified as the expected date of birth has passed, and the baby is in no hurry to make happy the mother and other relatives with his birth, you should not be in a hurry with the conclusions - up to 42 weeks pregnancy It is considered not post-worn, but prolonged. In the obstetric sense, they say about postponing when there are 42 weeks of pregnancy, but there are no signs of labor.

The reasons that can lead to this are quite difficult to study and analyze. But most often the following factors are considered.

• Error in setting the deadline. This could happen only if a woman does not remember the date of the beginning of her last before conceiving menstruation or her irregular cycle. In this case, the period will be adjusted according to the ultrasound, and what to do if the baby is too large, because the term will be set longer than it actually is. In fact, this situation is the most innocuous, because, in fact, there is no change. It exists only on paper.
• Large fruit. Children whose weight in the last weeks exceeds 4 kilograms are in no hurry to be born, and this is a fact.
• Low activity. Women who do not move much, do not do gymnastics, try not to walk, very often face the fact that labor activity does not occur within the appointed time.
• Unwillingness to give birth. A woman may be afraid of childbirth or worry that she will have to immediately change everything in her life after the birth of the baby. All this at the psychosomatic level leads to prolongation of pregnancy and perenashivaniyu. Sometimes women have the idea to give birth for a New Year or for a spouse's birthday, but, unfortunately, the DA is a couple of weeks earlier. In this case, psychogenic post-pregnancy is also possible.
• Endocrine disorders. The woman may be impaired production of oxytocin, estrogen, with an elevated level of progesterone, which normally should decrease before childbirth, also prenatal preparation does not start at the biochemical level.

Prolonged pregnancy is dangerous because the placenta can not perform its functions normally, it has grown old, has reached the extreme point of its aging, and therefore the child in the womb lacks oxygen, nutrients, which is fraught with hypoxia and various damage to the functions of the central nervous system caused by hypoxic changes.

The child is cramped, but even these days, when the mother is “re-walking”, he continues to gain weight, which threatens the birth process - an episiotomy may be required or a cesarean section should be performed if the child is too large.

As you can see, there are factors that a woman cannot influence in any way, for example, heredity. But in most cases, it is still possible to prevent premature birth or prolonged pregnancy. If you have risk factors to give birth prematurely or “linger” on the way, it is worthwhile to discuss preventive measures with your doctor beforehand.

General tips are as follows.

• Get registered in female consultation as soon as possible.
• Visit the doctor regularly, do not refuse additional tests and examinations - the timed complications of pregnancy make it possible to take timely measures and reduce the likelihood of early or late birth.
• Be quite mobile, especially in the later periods: do your homework, do more walking, do gymnastics - this is not only an excellent training of muscles before childbirth, but also an auxiliary measure of preparing the cervix for childbirth.
• Eat balanced and correct, try to saturate your food with vitamins, take vitamin preparations, if recommended by a doctor.
• Lead a healthy lifestyle.
• Pay special attention to psychological preparation for bearing and childbirth. A psychologist can help in this, who receives free admission at any antenatal clinic.