Calculate the baby's date of birth by monthly. PDR: when will the baby be born? What is PDR, what is an "online calculator"

Hello dear readers! Today I propose to talk about a very intimate, but important topic that worries almost every expectant mother - "How to correctly calculate the due date?" The birth of a child is the main event in a woman's life. For example, I was really looking forward to him, and at the same time I was afraid. Then my gynecologist told several ways that helped me to accurately calculate this date. I will gladly share this information with you. Are you already curious? Then let's start.

Determine the day of birth by the day of conception

Determining the exact date of birth of a child by the date of pregnancy is the most common method used by many expectant mothers. Add 9 months to the estimated date of conception, and you're done! Did you also calculate the time of delivery by this method? I hasten to upset you - these are incorrect calculations! The thing is that the process of carrying a child lasts 280 days, not 9 months.

Your personal ovulation calendar will help you determine this important day. The thing is that the moment of fertilization of the egg sometimes does not coincide with the time when the decisive sexual intercourse took place. Did you know that sperm cells can live in a woman's body for up to 7 days, and stubbornly "wait" when fertilization can be carried out?

Most often, it is the day of ovulation that is the day of conception. It is enough to add 280 days to it, and you will know when day "X" comes.

How to correctly calculate the due date

If you did not manage to carry out the appropriate calculations by the date of conception, use your personal menstruation calendar to calculate the baby's birthday. Every girl has it. Is not it? Any gynecologist will tell you that the regularity of the menstrual cycle is very important.

Doctors calculate the time of delivery using a special Negele formula. This method is suitable only for those girls whose menstrual cycle works like a clock and lasts 28 days. Let's try to use the formula together with a specific example.

The general wording is as follows - from the first day of the cycle, you need to subtract 3 months and add exactly 7 days. For example, my last period started on September 28th. I subtract 3 months from this date - it turns out June 28. Add 7 days, and we get the date - July 5th. This is a very simple yet effective way. Believe it or not, the time I calculated exactly coincided with the birthday of my baby.

Ultrasound is the best way to determine the "X" day

Medicine does not stand still. Gradually, new equipment appears, which allows you to carry out the most accurate studies of the body of a future woman in labor. With the help of an ultrasound examination, the gynecologist can determine the size of the fetus, and from this data establish the PDD (estimated date of birth).

I had different periods for menstruation and ultrasound, so I had to use another method, which I will discuss below.

In order for the survey results to be as accurate and truthful as possible, you need to perform. If you see your doctor too early, he will not be able to see anything, as the fetus is very small in early pregnancy. The ideal time to determine the PDD by ultrasound is 10-14 weeks.

The main thing is not to miss this moment, since then the baby will begin to actively grow and develop, and his physiological changes will depend solely on the individual characteristics of the organism. If you sign up for the first ultrasound examination in the 2-3 trimester, the gynecologist will not be able to determine the PDD accurately.

The baby moved in the stomach - it's time to calculate the exact due date

Did you know that you can also find out the PDR by the movement of the fetus? It is about this method that I promised to tell you at last. Well, promises must be kept! Of course, this method can be considered rather approximate and imprecise, but it has a place to be. The thing is that a girl who gives birth for the first time feels the fetal movement a little earlier than a mother with experience.

Be sure to remember the day when you first felt that the baby inside you began to move. One of these methods can be used:

If you will be giving birth for the first time, add 20 weeks to this date;
A girl who already has children must add 24 weeks to this date.

The method for determining the PDR by the first movements of the fetus is considered the least accurate.

If you had an irregular cycle before conception, be sure to warn your gynecologist about this. A very unpleasant situation happened to my friend during pregnancy. The fact is that her menstrual cycle is not 28, but 40 days. The doctors did not take this fact into account, and calculated the start date of the contractions, which turned out to be incorrect. As a result, the "X-day" came, and her labor activity did not begin.

The doctors already wanted to inject drugs for stimulation, but she managed to point out the error in the calculations in time. This is how useful it can be to independently calculate the time when the baby will be born! Thank God my friend and her baby are fine. The birth was easy, but she was scared in earnest. Now do you understand how important it is to correctly calculate the DA? Your health and the life of your newborn can depend on it.

Well, my dear future mothers! I wish you patience, calmness and good health. There is no need to be afraid of childbirth, and then it will pass quickly and easily. Perhaps you know other methods for determining the date of birth of a child? Share them in the comments and be sure to visit our blog more often. Many more interesting and useful things are waiting for you.

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Calculator PERIOD OF PREGNANCY

For many women, the feeling of an impending or already begun pregnancy occurs before the test shows two stripes - that is, even before the actual delay. Scientists cannot yet provide an explanation for these correct premonitions, however, the concept of the Early Pregnancy Factor has already been introduced into the scientific lexicon, which describes the chemical reactions of the mother's body in response to conception after only a few hours. Currently, there are already tests for the detection of the Early Factor hormone in the female body, but due to the significantly expensive cost, these tests are not produced on an industrial scale.

On average, childbirth occurs 10 obstetric months (280 days) after pregnancy, when the baby is ripe for birth. However, it should be noted that 280 days is a conditional number of days of bearing a child. All female organisms are different, and all babies mature differently in their mother's tummy. Someone will need 280 days, while others will be "ready" in 240 days. Only 2% of newborns are born on a precisely calculated day. Most of the kids are two weeks earlier, or a few days later. The duration of pregnancy and childbirth is calculated based on the date of the start of the last menstruation.

If we take into account all the changes that occur with the baby almost every day during pregnancy, and especially the first trimester, then in general these processes can be compared in importance and complexity, in depth with the birth of a new universe. Every day of a little crumbs inside you is not just a step, it is a huge leap forward, a breakthrough. The birth of a new life, despite the scale of its accomplishments, does not require any external efforts for itself .. everything happens under the cover of secrecy. After all, the woman herself learns that conception has occurred only after some time. Thanks to modern technology, scientists have managed to study a little the great mystery of birth - that where EVERYTHING begins. Enter your data and flip through the pages of the calendar of the development of human life throughout pregnancy. Believe me, amazing discoveries await you!

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In this article:

The estimated date of birth begins to interest a woman from the first day she found out about her situation. The approximate birthday of a child can be calculated in several ways, but none of them can boast of 100% accuracy. Many factors can influence the pregnancy process, and labor is often premature or late.

What determines the term of delivery

Even in a healthy woman carrying a healthy baby, the date of birth may deviate from the estimated date and depends on:

from whether she gives birth in or;
from the duration of the menstrual cycle;
from heredity and other individual characteristics of the mother;
from the features of the intrauterine development of the baby;
on how many children are in the womb.

In the presence of chronic diseases in a woman, impaired intrauterine development of the child, acute diseases or injuries during pregnancy, the term of delivery may significantly deviate from the planned date.

Methods for determining the date of birth

The most common methods for determining the expected due date are:

by the date of the last menstruation;
by the time of ovulation;
by date of conception;
by ultrasound;
by the size of the uterus;
by the first movement of the fetus.

Let's consider each in more detail.

By the date of the last menstruation

The date of birth by menstruation is the most common way of determining.

It has been used by obstetricians and gynecologists for many decades because:

not all pregnant women know the time of the last ovulation or the date of conception during regular sex life, but everyone remembers when they had their last period;
this is a fairly accurate method.

To determine the day of birth, you need to remember the first day of the last menstruation, add 1 year to this date, then subtract 3 months, and then add 1 week. The calculated date will be a guideline for the expected birth. Another way of determining: add 9 months and 1 week to the first day of the last menstruation.

By the time of ovulation or anticipated conception

The method of calculating the date of birth by the date of conception can be used with a planned pregnancy, when a woman has specially calculated the days of ovulation and knows them. It is during this period that conception occurs. To the first day of ovulation, add 266 days and calculate the date of delivery according to the calendar. This method is called embryonic.

By date of intercourse

This method is convenient to use with irregular or rare sexual activity. In this case, the woman knows which day in her life was decisive. It's very simple - 266 days are added to this date. This method is closer to embryonic. The dates of birth calculated in these two ways may differ by only a few days, because the dates of intercourse and conception often do not coincide. Not everyone knows that some sperm are able to live in a woman's body for up to 9 days, waiting in the wings.

By ultrasound

Using an ultrasound scan, the doctor can determine the approximate date of delivery, based on the established age of the fetus. This is most precisely established in the first trimester of pregnancy. In the future, there may be an error from several days to 3 weeks.

Largest uterus

The ancient medical method was the approximate determination of the gestational age and, accordingly, the expected birth by the size of the uterus. As in the previous case, it is possible to more accurately determine the time of delivery in the early stages of pregnancy. In the future, the size of the uterus depends on many factors (the size of the fetus, the amount of water). In addition, this method is only suitable if there is 1 baby in the uterus.

At the first movement of the fetus

An ancient folk way of guessing the date of birth is to wiggle the baby. After the disappearance of menstruation, a woman could only suspect about the presence of pregnancy, but when the fetus began to move, this was an absolute sign.

The woman added 20 weeks to this date and could quite accurately guess the due date with minor errors. It should be borne in mind that multiparous are already familiar with the feeling of fetal movement in the uterus and they usually feel it 1-2 weeks earlier than primiparous.

Efficiency of calculations

The exact day of delivery cannot be determined because the normal time for delivery is between 38 and 42 weeks of gestation. Thus, as many as 28 days can be considered the date of delivery "on time". However, in the normal course of pregnancy, different calculation methods are approximately the same and circle around the same date in the range of +/- 14 days.

Gynecologists still officially use the calculations for determining the possible day of birth by the last menstrual period, therefore this period is called obstetric. This method in about 20% of cases guesses the date of birth with an accuracy of +/- 5 days, and this is a fairly high percentage. The exact coincidence of the date of birth and obstetric term is about 5%.

How the features of the menstrual cycle affect the date of birth

Regardless of the duration of the menstrual cycle, the obstetrician-gynecologist applies the formula for calculating the due date by the date of the last menstruation. Accordingly, women with a short cycle and a long one will have the same due date. However, the date of ovulation is different for them, therefore, conception and delivery will be different.

With a short menstrual cycle (24 days) ovulation occurs on the tenth day. Fertilization takes place on the days of ovulation. Therefore, the actual term in women with a short cycle will be expected a week earlier. The due date is calculated using the following formula: the date of the first day of the last period plus 1 year and minus 3 months.

Long cycle (35 days) ovulation occurs on the twenty-first day. The birth will be a week later than the gynecologist calculated. A woman can calculate the date in this way: the date of the first day of the last menstruation plus 1 year, minus 3 months and plus 14 days.

Calculate the date of birth with an irregular menstrual cycle with large jumps follows the classic formula.

When you can't use the obstetric calculation method

The obstetric method of determining the date of birth by the last menstruation is the most common.

But it is not possible to use it in the following cases:

when pregnancy occurs immediately after the previous birth, and there has been no menstruation yet;
with severe menstrual irregularities, when the interval between menstruation can be more than several months, as is the case with menopause or various female diseases, for example, polycystic ovary disease or hormonal disorders.

What can be deviations from the terms

Carrying a child lasts 9 calendar months, or 10 lunar months (28 days each), or 280 days.

Childbirth is classified into urgent, premature and late:

Childbirth at 38-42 weeks is a normal period. Statistically, 70% of mothers give birth in the 39-41 week range. Primiparas often give birth 1 week later than the normal due date. But with repeated births, on the contrary, women are more likely to give birth before 39 weeks.
Childbirth after 42 weeks is late. The child is considered to be post-term. There are about 9% of such births.
Childbirth before 38 weeks is premature. The viability of the baby depends on the gestational age at delivery. The closer this period is to normal, the better.

Everything is individual, and in case of premature birth, a completely healthy and mature baby can be born, more often this happens over a period of more than 35 weeks. If the baby is underweight - less than 2500 grams, he will be considered premature.

The second degree of prematurity is established when the term of delivery is from 32 to 35 weeks and the weight of the child is less than 2000 grams. However, he also has a lot of chances to "mature" and gain weight after birth without the use of life support hardware.

With premature birth from 28 to 31 weeks, the child will be with grade 3 prematurity and low body weight (from 1000 to 1500 grams). Such children are successfully nursed in perinatal centers.

When a baby is born at a period of 22-28 weeks, he will have a 4th degree of prematurity. The baby has extremely low body weight and undeveloped lungs. There is no surfactant substance that ensures free breathing of the child.

Previously, the fruit was considered viable from 700 grams, now - with a mass of 500 grams or more. Such children are cared for in intensive care units using special transparent plastic boxes - incubators, which provide the necessary temperature, humidity and sterility of the environment. The baby is connected to a ventilator, feeding is carried out intravenously or through a tube, the necessary drug therapy is provided.

A baby born earlier than 22 weeks will not be viable due to severe immaturity. Currently, medicine is not able to leave such babies.

Causes of premature birth

The total share of all preterm births accounts for about 10% of cases. The cause may be maternal or fetal abnormalities, or a combination of various factors.

The most common ones are:

Social and household - smoking, alcohol abuse, drug use, stress, extreme physical activity, malnutrition and hypovitaminosis.
Pathology of the uterus - the consequences of abortions, other operations on the uterus, hypoplasia, endometritis, endometriosis.
Pathology of ongoing pregnancy - placental abruption, oligohydramnios, premature rupture of amniotic fluid, inflammation of the membranes, multiple pregnancies,.
Diseases of the mother - diabetes mellitus, hypertension, rheumatism, bronchial asthma, severe anemia, mental disorders, etc.
Multiple anomalies in the development of a child, incompatible with life, at present, the latter is rarely the cause of premature birth, since women are trying to terminate pregnancy early for medical reasons.

In the presence of such risk factors, a woman should be especially careful, since she has a high risk of having a premature baby. She may have to spend some time saving.

Determining the expected due date is an important task. But in any case, the calculated period is approximate. It depends on many reasons. Therefore, with a long gestation period, a woman should listen to herself and expect childbirth, starting from the 37th week of pregnancy, or even earlier.

Helpful video on calculating due date

If the delay in menstruation is small and there are no complaints of feeling unwell, then you should not rush to an appointment at the antenatal clinic yet. But an inner feeling already tells you that a miracle has happened and soon you will become the happy parents of a wonderful baby. Any woman in this position seeks to get an answer to the question: when exactly will the time of childbirth come? Our service allows you to determine the exact date of birth of an unborn child in a matter of minutes.

Calculate due date online

At the heart of any method for calculating the date of expected birth is the idea of \ u200b \ u200bthe normal stages of pregnancy, which usually lasts about forty weeks (in some cases, a deviation of several weeks is also not a pathology). The starting point is the start of the last menstrual period, and it is likely that the expected event will take place in exactly 280 days or 40 obstetric weeks.

Using the online calculator presented on the website, you can easily and easily find out the likely date of the upcoming birth. All that is required of you is to enter the necessary data into the corresponding windows of the calculator, and the necessary calculations are performed by the computer. The principle of the calculation is very simple: the date of the beginning of the last menstrual bleeding and the traditional 280 calendar days are summed up.

The resulting date is approximate and corresponds to an ideal medical condition. The actual dates may differ slightly depending on the individual characteristics of the woman, her state of health and the general course of pregnancy.

Pregnancy calendar, how to calculate the date of birth by menstruation

Find the date of your last period in the blue line of your calendar. The date below it (red or yellow) will be the due date.

Calculate due date by date of conception

Not every woman knows exactly the day when conception occurred, so doctors cannot reliably determine the so-called "embryonic" gestational age. However, if the time of fertilization is known, then the results of calculating the time of birth will be much more accurate, because each child needs the same period for full intrauterine development. In such cases, you need to add 280 days again, this time to the date of conception.

When calculating the date of birth by the day of fertilization, minor errors are allowed, because pregnancy could not have occurred on the day when the corresponding sexual intercourse occurred. Studies show that the conditions in the vagina are quite favorable for the sperm, so they can stay there for several days before they fuse with the egg. The error is one to three days, but no more. Thus, the date of conception determined by a similar method is also indicative.

Calculate due date by ovulation

You can determine the date of birth of a baby by calculating the day of ovulation. This method is not suitable for everyone, because only a small number of women carefully monitor their menstrual cycle, and even more so - they keep the ovulation calendar. If you know at least the approximate date of ovulation (with a constant cycle of 28 days, it falls in its middle), you can get a more or less accurate date of birth. To do this, add 280 days to the ovulation date.

Of course, the most accurate results can be obtained if you have the maximum amount of initial data. The best option seems to be a combination of all the presented methods for calculating the date of birth. But in any case, a few days of waiting is not a big problem, because the main thing is the birth of a healthy child and the subsequent pleasant chores.

Video: How to determine the due date.

Estimated due date(PDR) is considered the day when the gestational age is exactly 40 weeks. Although a full-term pregnancy is considered already upon reaching the full 37 weeks, and in some cases a healthy full-term baby can be born at 42 weeks of gestation, it is still customary to focus on 40 weeks, since most births begin precisely at this time.

The importance of calculation estimated date the birth of a baby is beyond doubt, and the point here is not only the desire of the parents to prepare for the appearance of a new family member. The medical side of the matter is also important. Let's list the reasons why a doctor leading a pregnancy needs to know the expected date of birth.

Fetal growth and development... It is important for a doctor who monitors the course of pregnancy to know how much the developing baby corresponds in size to the gestational age (which is calculated based on the expected date of birth) in order to timely diagnose such a serious complication as intrauterine growth retardation (IUGR), which is a consequence of placental insufficiency (pathology , in which the placenta is defective in providing the fetus with everything necessary for growth and development). Timely adequate diagnosis, and, consequently, treatment of this complication is of great importance for the further full development of the baby.

Prevention of pregnancy complications... In the process of observation, the obstetrician remembers that at various stages of pregnancy, the development of certain complications is possible, in connection with which the timing has been determined in which diagnostic measures must be taken to identify complications, their prevention and treatment (for example, prenatal screening - diagnosis congenital malformations of the fetus - should be carried out at clearly defined periods of pregnancy, and if these periods are not observed, its diagnostic value is sharply reduced). With diseases such as diabetes mellitus and hypertension - if the course of the disease worsens or the treatment does not give a positive effect - it may be necessary to deliver before spontaneous labor begins. Then the doctor needs to know in order to ensure the maximum possible degree of fetal maturity in this clinical situation.

When to go to the hospital

If there are indications for early hospitalization before delivery, it is important to correctly determine the timing in which the pregnant woman should go to the hospital... Indeed, with too late hospitalization (for example, on the eve of a planned cesarean section), there is a risk of not having time to carry out the required amount of examination and preparation for delivery, and too early hospitalization is not advisable, since a long stay of the expectant mother in the hospital can lead to an increased level of anxiety, stress the day before childbirth. The timing of antenatal hospitalization for various complications during pregnancy may vary. For example, with diabetes mellitus, it is necessary to hospitalize a pregnant woman no later than 36 weeks. With a transverse position of the fetus and placenta previa, the expectant mother should be in a hospital no later than 37 weeks (since during this period the body prepares for childbirth, which is a great danger due to prenatal rupture of amniotic fluid in the case of a transverse position of the fetus and the development of bleeding during presentation placenta). Women with breech presentation and anatomically narrow pelvis are sent for antenatal hospitalization at 38–39 weeks of gestation in order to have time to conduct a full examination, choose a method of delivery, and prevent pregnancy overdue.

How to calculate your due date

For determining expected due date several methods are used.

Obstetric term(by the date of the last menstruation). It is generally accepted to consider the date of the first day of the last menstrual period as the reference date for the menstrual cycle - that is, the complete menstrual cycle is calculated as the interval from the first day of menstruation to the first day of the next menstruation.

For calculation expected due date by the date of menstruation, there are two ways:

280 days are added to the date of the first day of the last menstruation (on average, pregnancy has this duration, counting from the date of menstruation).

Formula Negele: from the first day of the last menstruation, 3 months are subtracted and 7 days are added. For example, the last menstruation was on May 10 - subtracting 3 months, we get February 10, and adding 7 days, we get February 17 - this will be the estimated date of birth by the date of menstruation (we will assume that on February 17, the gestation period will be a full 40 weeks, and therefore, around this time, labor should begin).

Fetal term(by date of conception or by ovulation). The likelihood of pregnancy is highest on the day when ovulation occurs - the process of the release of a mature egg from the ovary. This usually occurs in the middle of the menstrual cycle (for example, if the menstrual cycle is 28 days, then ovulation occurs on the 14th day, and if the cycle is 32 days, then on the 16th day).

Given that the egg is capable of fertilization within 24 hours after ovulation, and the life span of a sperm is on average 72 hours (in some cases it can reach 4-5 days), the probability of fertilization is not 1 day, but much earlier - starting from 9 -10th day of the menstrual cycle (with a 28-day cycle). This circumstance significantly complicates the establishment of the expected due date by the date of conception. It is possible to establish the due date of conception when a woman knows exactly the date of ovulation (for example, she monitored the basal temperature or, for medical reasons, ultrasound monitoring of folliculogenesis, the process of egg maturation, was carried out). To determine the PDD, 266 days (since this is the true duration of pregnancy) or 38 weeks are added to the date of conception.

With a regular menstrual cycle (lasting 28 days), there is no difference between calculations by the date of the last menstruation and the date of conception, therefore it is most convenient and informative to determine by the date of menstruation.

By the date of the first appearance in antenatal clinic... This method of determining the duration of pregnancy and childbirth will be as informative as possible if the expectant mother consults a doctor before 12 weeks of pregnancy. When registering, in order to be sure of the fact of pregnancy and to establish its duration, the doctor will conduct an examination on a gynecological chair to determine the size of the uterus. It begins to increase from 5-6 weeks of pregnancy, acquires a spherical shape. In addition, during pregnancy, the uterus becomes soft (outside of pregnancy, the uterus has a pear-shaped and dense consistency).

Determining the size of the uterus during a gynecological examination, the doctor specifies which gestational age corresponds to an increase in the uterus. For example, at 5-6 weeks, the uterus becomes the size of a hen's egg, at 7-8 weeks - the size of a goose's egg, by 12 weeks it reaches the size of the newborn's head and its bottom (this is the name of the upper part of the uterus) is already possible to palpate (feel) through the front the abdominal wall without resorting to vaginal examination. Starting from the second trimester, according to the height of the fundus of the uterus, you can roughly determine the gestational age: by 16 weeks, the bottom of the uterus is in the middle of the distance between the bosom and the navel, by 24 weeks - at the level of the navel.

It is important to remember that the longer the gestation period, the higher the error may be in determining it according to this parameter, since the height of the uterine fundus depends on many individual characteristics: the number of births in the anamnesis, the size of the fetus, gynecological diseases (for example, with uterine myoma, the size of this organ will be more than the norm for a given period), the anatomical features of the organism of the expectant mother, etc. Therefore, the examination performed before 12 weeks of pregnancy is of greatest importance for determining the PDD upon arrival at the antenatal clinic, then the doctor will be able to determine the duration of pregnancy by the size of the uterus ...

According to ultrasound data... Determination of the gestational age and expected due date it can be done quite accurately if an ultrasound scan is performed in the first trimester of pregnancy (up to 12 weeks). When conducting an ultrasound examination at the earliest stages (and it is possible to see the ovum by ultrasound from 3-5 weeks of pregnancy, the embryo begins to be clearly visualized a little later - starting from 5-6 weeks of pregnancy), the average inner diameter of the ovum and the coccygeal-parietal size are measured CTE of the unborn child. For each gestational age, there are certain KTP standards, measured in millimeters, by comparing which with the data obtained, you can fairly accurately establish the expected date of birth.

In the second and third trimesters gestational age It is established based on the measurement of certain fetal dimensions: such as biparietal size (the distance between the parietal tubercles, or large transverse size of the fetal head), head circumference, abdominal circumference, fetal chest and abdomen diameter, femur length. The data obtained also allow us to judge the duration of pregnancy, but it must be remembered that the larger it is, the greater the likelihood of an error. This is due to the fact that as the fetus develops, depending on the characteristics of the course of pregnancy, the presence of diseases of the mother, hereditary factors, the size of the fetus, which is used to judge the duration of pregnancy, will differ significantly. One mother will have a child weighing 2600 g and height 48 cm, and another - 4500 g and height 57 cm, which is completely normal, since all people have individual anthropometric characteristics. Thus, it is possible to determine as accurately as possible the gestational age according to ultrasound data in I trimester of pregnancy or around 20 weeks, when there is the greatest agreement between fetal size and gestational age.

By the date of the first stir fetus. PDR can also be determined by such a parameter as the date of the first movement of the fetus. In this situation, it is more correct to talk about the date when the pregnant woman first felt the fetal movement, since the fetus begins to actively move in the uterus from 8 weeks of pregnancy, it is just that the mother does not feel this due to the too small size of the child. It is believed that primiparous women first feel fetal movements on average from 20 weeks of pregnancy, and multiparous women - from 18 weeks, therefore, to determine the expected term of birth according to this parameter, 20 weeks are added to the date of the first fetal movement in primiparas, and in multiparous women - 22 weeks.

It should be noted that this method definition of DA considered additional, or auxiliary, since fetal movement is a very subjective sensation, moreover, future mothers do not always celebrate it for the first time in the above terms. For example, primiparous women may first feel fetal movements in later stages of pregnancy - after all, this is still an unfamiliar sensation to them, and at first they may confuse it with intestinal motility or simply not notice. Women with a pronounced layer of subcutaneous fat may first feel fetal movement 1-2 weeks later. Multiparous women, on the other hand, may notice the first movements at an earlier date (at 16-17 weeks), since they already know how this happens. These circumstances may reduce the accuracy of determining the expected due date by the date of the first fetal movement.

Why calculate the DA by several parameters?

The need to calculate estimated due date according to several methods is simultaneously due to the following factors. Firstly, despite the availability of the most modern methods for assessing the duration of pregnancy, it is almost impossible to predict when a woman will begin labor (with an accuracy of the day). Secondly, some of the data on which it is customary to calculate the estimated date of birth, for various reasons, may be uninformative. For example, with an irregular menstrual cycle, the calculation of the PDD by the date of the last menstruation will be inaccurate, and with a late first visit to the antenatal clinic, the presence of gynecological diseases (uterine fibroids) or overweight, it will be difficult to determine the duration of pregnancy by the size of the uterus. Given these circumstances, the doctor sets the expected date of delivery based on the maximum amount of data to clarify the time interval in which labor is most likely to begin. As a result expected due date most often it is defined not as one specific number (for example, January 15), but as a time period (for example, from 12 to 17 January).

Nevertheless, even when the estimated date of birth is correctly calculated according to all the data, not all pregnant women begin to give birth, since the duration of pregnancy in each case depends on many factors. That is why the date of birth is called the estimated date.

Duration of pregnancy, and therefore, the period when regular labor will develop is individual, moreover, it is calculated based on the fact that labor will begin after reaching the full 40 weeks, but pregnancy is considered full-term after 37 weeks, so labor can begin in 2-3 weeks before the expected due date. A variant of the norm is the development of labor in the 41st week of pregnancy.

Thus, on duration of pregnancy and the onset of labor is influenced by many factors, among which the characteristics of the history play an important role - the age of the expectant mother, the number of previous births, the presence of miscarriages, premature births and / or abortions in the past, existing chronic diseases. In addition to these features, for a period onset of labor the peculiarities of the course of this pregnancy also affect. For example, with multiple pregnancies, childbirth often begins earlier than with a singleton, and the gestation period is inversely proportional to the number of fetuses (the more fetuses, the shorter the period), which is due to overstretching of the uterus. With the development of placental insufficiency (pathology of the course of pregnancy, in which one or more functions of the placenta are disturbed, leading to insufficient provision of the fetus with everything necessary for growth and development), both early development of labor and an increase in the duration of pregnancy by 1-2 weeks are possible.

Despite the impossibility of absolutely accurate determination of the date of birth, it is still necessary to correctly calculate the DA. Focusing on the expected term of delivery, the degree of biological readiness of the organism of the expectant mother for childbirth (determined by the doctor according to a number of signs, one of the main is the degree of maturity of the cervix - the presence of biological readiness for childbirth is the key to the physiological course of childbirth and a favorable outcome for the mother and fetus) and the state fetus, the doctor will be able to timely resolve the issue of the need for preparation for childbirth, prenatal hospitalization, drug treatment, etc.

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