How to calculate your due date based on your last menstrual period. How to determine the due date: methods

There are several ways to calculate your due date. However, oddly enough, only an experienced gynecologist-obstetrician can accurately determine the date of birth, since many factors, including heredity, influence the duration of gestation. By the way, the international community of gynecologists and obstetricians recently recognized a full-term pregnancy at a period of 38 weeks, and not just at exactly 40 weeks.

In a word, even if you can, you shouldn’t relax. And within plus or minus two weeks from the scheduled date, you need to be ready for childbirth, that is, collect the necessary things, sign an exchange card at the maternity hospital, talk with the doctor who will deliver the birth, if this is part of your plans.

Today medicine knows many ways to calculate the due date. This can be done by the date of conception, by the date of ovulation, by the first day of the last menstruation before pregnancy, by the date of the first fetal movement. More accurately, the doctor can name the preliminary date of birth during an ultrasound examination (ultrasound) or during a gynecological examination, when measuring the size of the uterus. There are also so-called folk methods for calculating the date of birth, when an obstetrician can determine the date of birth by the expectant mother - the shape of her tummy and its prolapse and elevation. But the midwife’s experience is very important here, without which it is unlikely that it will be possible to calculate the date of birth. And this method “works” only on the eve of childbirth.

It is important to know!

The expectant mother needs to know that, according to statistics, only 4% of pregnant women give birth on the day that the doctor prescribed for them. That is why the date of birth, which appears on the exchange card, is called preliminary. So there is no need to worry if labor begins a few days or even weeks earlier. On average, pregnancy lasts 10 lunar months, that is, about 280 days. However, here everything is individual. As a rule, the date of birth is “determined” by the baby himself, when he finally matures and prepares for birth.

The easiest way to calculate the preliminary date of birth (PDD) is by the day of conception. If, of course, you know exactly this significant day. If you know the date of conception, then simply add 280 days to it - the average period of pregnancy - and get the possible date of birth of the baby with variations of plus or minus two or three days.

Ovulation, that is, the day when the egg leaves the ovary, on average occurs on the 14th day of the menstrual cycle, although variations are possible here too. Determining the day of ovulation is quite simple, knowing the length of your monthly cycle and the first day of your last menstruation. However, if the cycle is longer - 30 days, then ovulation will occur on the 15th. It is very difficult to calculate this day if the cycle is inconsistent.

It is also necessary to take into account the fact that fertilization can occur 2-5 days before or after ovulation, since sperm can survive this time in a woman’s body. The easiest way to determine the day of ovulation is with the help of special tests that are sold in pharmacies. So, knowing the day of ovulation, add 280 days to the date - the duration of pregnancy, and get a preliminary date of birth.

Define Ovulation can be done using the website website.

As a rule, the date of preliminary birth is most often calculated from the first day of the last menstruation, adding 280 days to the date. Usually it is this date that the gynecologist writes down on the exchange card. Unless, of course, new circumstances were revealed during the ultrasound.

You can also calculate the child’s date of birth as follows: subtract 90 days from the date of the last menstruation (that is, 3 months) and add 7 days. For example, if the last cycle was January 31, then birth will occur approximately November 7 of the same year.

This formula is good for those who have a regular menstrual cycle of 28 days. With a longer cycle, labor will occur a little later, with a shorter cycle - a little earlier.

Another way to find out when your beloved baby will be born is by the baby’s movements. During the first pregnancy, the baby's first kicks are usually at 18-20 weeks. Those who become mothers for the second time may feel fetal movements at 16-18 weeks. To this date you need to add 20 weeks for those who give birth for the first time, and 22 weeks for those who give birth again. This will be the preliminary date of birth of the child.

Of course, it often happens that a woman cannot name the exact date when she first felt the baby’s movements. And this is the main problem with such calculations.

Mom, under the nickname KATALINA, shares her experience:

“During my first pregnancy, my mother calculated my due date based on the first movement, and I gave birth right to the day :) Although the dates were different according to menstruation and ultrasound. I remember I started moving at 18 weeks, and it seemed like she was gaining another 20 weeks. I know for sure that if you started moving at 16 weeks, then you need to add 22 weeks, if at 20 weeks, then add 18 weeks, at least that’s what it was written in one of the parenting magazines.”

According to gynecologists, the most accurate way to calculate the due date is an ultrasound examination. Already at the first ultrasound, which is usually done up to 12-14 weeks, the doctor calculates the PDR, taking into account the size of the fetus, which in the early stages makes it possible to fairly accurately determine the preliminary date of birth.

During pregnancy, during the first examination, the obstetrician-gynecologist, as a rule, immediately determines the duration of pregnancy, taking into account the degree of enlargement of the uterus. According to the gynecological diagram of the relationship between the gestational age and the size of the uterus, the doctor puts a PDR.
Then, after the 20th week of pregnancy, during each of your visits, the gynecologist will measure the height of the fundus of the uterus to monitor the rate of pregnancy development and identify possible problems, since there should be certain indicators at each stage.

No matter how many women give birth, the debate among expectant mothers about how to determine the due date of a child continues for the same amount of time. The difference between your own calculations, ultrasound readings and doctor’s notes is completely confusing. How to determine the due date? Let's try to figure it out, because even in old books about obstetrics there are calculation schemes, and modern medicine should know this all the more.

How to calculate the due date - is there an accurate way?

Modern technologies provide women in labor with the opportunity to correctly determine the moment of birth of the baby in several ways:

Obstetric, which is calculated based on the last menstruation.
According to the primary movement of the fetus.
After visiting a gynecologist, who sets the date based on the examination.
Embryonic, which is determined by the date of ovulation.
Based on the results of an ultrasound examination.

In addition to the above methods, women in labor determine the required timing using a special online calculator. With so many different ways to determine pregnancy, doctors calculate with accuracy the baby’s birthday, according to statistics, only in 4 cases out of 100, because the duration of gestation is influenced by many different factors, and heredity in the first place.

The community of obstetricians recognizes pregnancy as full not only at 40 weeks, but also at 38, so the due date always moves forward by a couple of weeks in both directions. An experienced gynecologist sometimes determines the day of birth by the shape of the expectant mother's belly, but this method is only effective immediately before childbirth. Let's consider each option for determining the due date separately.

Determining due date by menstruation

This is an old method of calculation, but it is only suitable for those women who have a regular cycle. If your period sometimes comes late or early, there will be large discrepancies in the calculations. The easiest way to determine how much time has passed since conception. Do you remember how many days have passed since the first day of your period? The total number of days counted will indicate the gestation of the fetus.

The term is determined much more accurately using the Keller formula. If you add 280 days to the first day of your last menstrual period, you will get the baby's approximate birthday. Where did the number 280 come from? The average number of the sum of the life expectancy of the fetus and the period that passes before ovulation is taken. The average includes the following indicators:

the period from the conception of a child to his birth (266 days);
average menstrual cycle (28 days);
ovulation date (day 14 of the menstrual cycle).

The obstetric period is equal to the average duration of the menstrual cycle, therefore, when calculating, gynecologists are guided by the indicators of the obstetric calendar and 280 days. The lifespan of a sperm is several days, so even if the time of sexual intercourse is known, it is impossible to determine exactly when ovulation occurred. A baby is considered full-term if born between 38 and 42 weeks, so the error of this method is also two weeks. Using a special table shown in the photo below, the obstetric gestational age is determined.

Calculation of due date by date of conception

Determining the moment of birth by the day of ovulation or the date of conception is very simple. The body of a healthy woman is able to conceive a child only on certain days of ovulation, when the egg has matured and left the ovary. If the menstrual cycle lasts 28 days, then ovulation occurs exactly in the middle of the cycle. Many women say that they feel the moment of ovulation, so it is easy for them to predict the date of birth: at this moment, bloody, not profuse vaginal discharge begins, sexual desire intensifies and a heaviness is felt in the lower abdomen.

How to determine the exact due date if you know the day of ovulation? To do this, add 280 days to the middle of the menstrual cycle. In the same way, the due date is determined by the day of sexual intercourse, if it was a single one. But there is a high probability of inaccuracy here, since sperm live for several days. So, if sexual intercourse took place on the 14th day of the cycle, then conception occurred on the 16th or 17th day.

Determining the due date by the first fetal movement

This method has existed for many centuries, but this does not prevent it from being in demand. And if only a few modern women in labor determine the due date in this way, then when there was no diagnostic equipment, all women used it. The first movement of the fetus usually marks exactly the middle of pregnancy, so the due date is counted from this date. But experienced obstetricians doubt the accuracy of this method, and they have several reasons for this:

A thin girl leading a sedentary lifestyle feels fetal movement much earlier than planned.
Primipara women usually feel the first tremors a couple of weeks later than those who give birth again.
In fact, the baby in the womb begins to move already at the 12th week of pregnancy, but mothers do not feel this yet.

For these reasons, the method of determining a child’s birthday by the first movement cannot be called accurate. The error is especially large if the fetus matures for 41 or 42 weeks, which is considered quite normal. To prevent the doctor and mother from making the wrong decision regarding the fetus, there are more accurate ways to determine the gestational age, for example, ultrasound examination.

How to find out your due date using ultrasound

Even an experienced specialist will not tell the expectant mother the 100% exact date of birth of the child. At best, the due date is indicated with an accuracy of several days, because to a greater extent it depends on the woman in labor: her emotional state throughout the pregnancy and physical health. As statistics show, the method of ultrasound examination is particularly popular today. Greater accuracy of the examination is achieved from 6 to 12 weeks. At later stages, ultrasound is also ineffective as at earlier stages.

In the later stages, even with the help of an ultrasound, it is impossible to determine the exact day of birth of the child. After all, everything is individual: some babies are born weighing 5 kg, others weigh a little more than 2 kg at birth. Also, research in the field of obstetrics and gynecology shows that small women often give birth to large children and, conversely, large women in labor give birth to children up to 2 kg.

The specialist determines the age of the fetus by the size of its head and limbs, and based on the size of the mother’s abdominal cavity, the exact size of the embryo, the condition and size of the uterus, the doctor calculates the approximate moment of birth in any month of pregnancy. In any case, both doctors and expectant mothers believe the results of ultrasound examinations first and foremost.

Table for determining due date

There is another effective way to determine the approximate date of birth - by weight gain. Over the entire period of pregnancy, the expectant mother gains on average from 9 to 14 kg. If twins are expected, then the weight gained reaches 21 kg. In the first trimester, the weight practically does not change, in the second, about 1 kg per month is gained, and already in the third trimester, the woman gains weight rapidly - up to 500 g in one week.

Guided by a special table for determining the timing of childbirth, you can compare the readings of the numbers by weight during weighing. Obstetricians begin to use this table from the 7th month of pregnancy, when the expectant mother is actively gaining weight. According to this scale, a woman should gain about 20 g per week per 10 cm of height. Based on the total body mass index, female figures are divided into the following types in the table:

Thin – up to 19.8 (group 1)
Average build – from 19.8 to 26 (group 2)
Obese - from 26 (group 3)

Many women, especially those expecting their first child, do not understand why the doctor named this or that due date, although according to their calculations it turned out that the baby should be born earlier. There is no need to worry, the doctor was not mistaken, and neither were you. How can this be? The fact is that there is a true pregnancy period and an obstetric one; they differ from each other by two weeks.

For any pregnancy, the estimated delivery date is always calculated. There are several methods for calculating the approximate due date.

Embryonic. This is a real term, i.e. This is how long a normal pregnancy lasts. From the date of conception to birth, 266 days usually pass, or, in terms of weeks, 38 weeks.
Obstetric. This period is usually recorded in the patient's card. The doctor cannot know the date of conception of the child. Medicine is an exact science; it cannot rely on a woman’s assumptions. Therefore, obstetricians-gynecologists use their own method. The countdown is not from conception, but from 1 day of menstruation before pregnancy. This period differs from the true one; its duration is 280 days (forty weeks).

Calculation by day of menstruation

The most common method that helps to quickly calculate the expected date of birth is based on the last menstrual period.

Think back to the day your last period before pregnancy began. Mark this day on your calendar.
Now subtract three months (working backwards through the calendar).
Add seven days to the resulting date.

Let's say the last time your period began was on July 15th. We count down three months in reverse order - it turns out to be April 15. We add 7 days to this date. The baby's birth date is April 22.

You can quite accurately calculate the due date based on the date of your period if a woman has a regular cycle and it lasts from 26 to 28 days. If it is slightly longer, for example 35 days, the result that was obtained will be incorrect. In this case, conception should occur on the 21st day of the cycle, and not on the 14th, as in many women, i.e. labor may begin 7 days later. If the cycle is short, less than 24 days, then the due date also moves forward by about 7 days, they should begin earlier.

Calculation using a calendar

If you find it difficult to make these calculations or you doubt that everything is correct, use the birth calendar to calculate this day based on the date of your last menstrual period. The top line is the time of the onset of menstruation, below it is the expected date of birth.

Or you can use online calculators, which are available on many websites. It is enough to enter the date of the beginning of the last menstruation in a special window, after which the system will give the desired answer. Online pregnancy calendars are now very popular; they will not only help you calculate the due date, but will also tell you what is happening in the woman’s body. This way, the expectant mother will be able to monitor the development of her baby and find out what changes have already occurred. If you wish, you can even order your own individual calendar, which will show how the child grows in time.

Calculation by date of conception

How to correctly calculate the due date if your periods are irregular? There is another way that will help calculate the due date based on the date of conception. You need to remember on what day the child was conceived. Then add 266 days to this figure. This is how many days a woman usually carries a baby. You can also calculate the due date by weeks of pregnancy, because Sometimes it can be difficult to count the days. On average, pregnancy lasts 38 weeks after conception. Using the calendar, it is easy to calculate the due date based on the known date of conception.

Are these methods reliable?

If you calculate the due date based on your last period, will the baby be born on that day? No, according to statistics, only 5% of children are born on the “calculation day”, this is an approximate date, babies are born within a week (plus or minus) from this day (85%), and about 10% of children can be late by another week.

Also, if you correctly calculate the due date based on the day of conception, there may be errors. Not everyone can name the date of conception of a child, because... this date sometimes does not coincide with the day on which the intimacy took place. The sperm can remain in the body and fertilize a woman for 4-5 days after intimacy, i.e. a woman could have sex on one day and conceive a child later. But, even if the calculation was correct, the birth may be premature due to various illnesses, severe stress, etc.

Additional ways to determine pregnancy

A trip to the gynecologist. As soon as the expectant mother comes to the doctor, the gynecologist examines her and finds out what her gestational age is. Accurate results can be obtained between 5 and 12 weeks by measuring the size of the uterus. A pregnant woman's blood test for hCG is also important. This hormone is produced only in the body of a woman expecting a child; its concentration in the blood varies at different stages. The doctor has tables that indicate how much hCG should be present at a given period.
Ultrasound. The doctor must measure the size of the fertilized egg, as well as the embryo. Until 9-10 weeks, the indicators for all women at a certain period are the same. You can use them to find out the gestational age. Later this method will not work, because... after 10 weeks, the size of the fetus can vary significantly from woman to woman, depending on the mother’s weight, nationality and other factors that affect the weight of her baby.
At the first movement. It is believed that a mother expecting her first child feels 1 movement at twenty weeks, and other pregnant women at eighteen weeks. Based on this knowledge, you can calculate the date of birth: for a woman who is pregnant for the first time, add twenty weeks to this date, and for someone who has already given birth, add 22 weeks. But some mothers feel the baby moving already at 15-16 weeks, while others feel it after 20 weeks, so these numbers will be inaccurate.
There are many ways to calculate your due date. You should not hope that the child will be born on this very day, but it is important for a woman to know at least the approximate time frame in order to complete all her affairs, pack her things and prepare for the birth of the baby. This information is also necessary for the doctor who is conducting the pregnancy to make sure that it is proceeding normally.

As we can see, it is not difficult to make such calculations; you can calculate the required number in just a few minutes.

Finding out the due date is a natural desire of a woman carrying a baby. This helps to better prepare for the birth of a child and mentally tune in to the process of childbirth. If there are several ways to calculate the due date yourself.

Estimated date of birth (EDD) is the date when labor should begin after forty weeks of gestation. These are approximate figures, since thirty-seven weeks is the period from which the pregnancy is considered full-term. The baby can be born at forty-one weeks and even at forty-two weeks, and this is also considered a normal period, but usually doctors do not allow the expectant mother to go through such a long transition and stimulate labor artificially.

Not a single specialist, including the most highly qualified doctor, can give the exact date when labor will begin.

The time of birth of the baby is largely influenced by the individual characteristics of the expectant mother and the condition of the baby. For this reason, the day of birth can only be calculated approximately.

There are several methods for calculating your due date. It is recommended to use all methods at once in order to compare the results later.

By date of conception

This method can only be used by a woman who is sure on what specific day of intimacy conception occurred. Calculation of the approximate date of birth of the baby is carried out according to the formula:

“The day of conception + 266 days = day of birth.”

You need to add 3-5 days to the resulting date or subtract the same amount. This error is due to the fact that a man’s seed can remain viable in a woman’s body for a week.

If pregnancy occurs on this day, then the expected date of birth of the baby is calculated using the formula:

“Day of ovulation + 268 days = date of birth of the baby.”

The error is also 3-5 days.

By last menstruation

When calculating the date of birth based on the last menstruation, two methods are used.

280 days are added to the first day of menstruation. The resulting date will be the expected date of birth. The essence of this calculation is that the difference between the beginning of the cycle and the day of ovulation is two weeks.
According to Nägel's formula. It is based on the fact that the gestation period for a baby is 280 days. According to this, in order to calculate the expected date of birth of the baby, it is recommended to subtract 3 months from the first day of menstruation, and add a week to the result obtained. On this day, exactly one year from now, the birth should take place, taking into account the error of several days.

The use of any of the options is relevant only when a woman has a regular cycle. If menstruation begins at different times, the data obtained will be inaccurate with an error of thirty days.

When calculating the due date, medical workers usually use the second method.

An ultrasound scan shows the day on which ovulation occurred, as well as the gestational age. This is one of the few methods that determines the exact date of pregnancy to the day. To do this, it is recommended to carry it out in the first trimester. Knowing the period, the date of ovulation or menstruation is determined. This allows you to calculate the expected date of birth of the baby in several ways.

The ultrasound itself can also provide information about the day of delivery. To do this, the procedure is carried out after the 20th week of pregnancy. In this case, the specialist clearly sees at what stage of development the fetus is and can determine when it is time for the baby to be born.

If an ultrasound examination reveals that the baby has begun to develop faster, the specialist may be confused in his calculations. In this case, he states that the gestational age of the baby was incorrectly determined and moves the date of the start of labor.

According to the first movements

If the expectant mother was able not to miss the time of the baby’s first movement, confusing it with the natural processes occurring in the intestines, then she can calculate the date of birth of the child from this moment.

According to statistics, the baby begins to move after the 20th week of conception, if it is the first pregnancy. If the mother carries the baby for the second and subsequent times, the baby will make itself known after the 18th week. As practice shows, a woman can feel the first movements 14 days ahead of schedule. This also happens two weeks later than expected. For this reason, the error in calculating the approximate date of birth is plus or minus 14 days.

To find out using this method what date the baby should be born, during the first pregnancy, 20 weeks are added to the date of movement. If this is the mother’s second birth and subsequent ones, then 22 weeks are added to the date. The resulting figure will be the estimated date of onset of labor.

Based on the results of a gynecological examination

Based on the results of the examination, an experienced doctor can determine what date a woman should give birth. The specialist makes his assumptions based on the size of the uterus and its condition. The technique is relevant only in the first trimester of pregnancy.

If a woman arrives later than this period, even a gynecologist with extensive experience will not say when the baby will be born, since the size of the uterus changes differently for each woman. The dimensions of the organ are influenced by the individual characteristics of the expectant mother and a number of other factors.

When determining the expected date of birth, the doctor is based on the duration of pregnancy at 40 weeks. This is the average norm for carrying a baby.

In the early stages of conception, a gynecological examination does not provide information about when labor will begin. This is due to the fact that the uterus cannot be felt through the abdominal wall during external examination. In this case, the due date can be determined by an obstetric examination. Such data are also approximate, since the result depends on the doctor’s internal feelings and his work experience.

Clinical studies show that when pregnancy reaches four weeks, the uterus becomes the size of a chicken egg. In the eighth week of gestation, the baby's dimensions increase to the size of a goose egg. At the twelfth week of pregnancy, the uterus enlarges to such a state that it reaches the edge of the pubic bone.

In this way, the doctor will determine the date of birth of the baby only in the first trimester. If the expectant mother applied at a later date, she is recommended to use other methods to correctly determine the due date.

Which method is considered the most effective?

Ultrasound examination is considered the most effective method for determining the date of onset of labor.

It shows the condition of the placenta, how the baby’s head is positioned relative to the entrance to the pelvis, the level of development of the child and the size of the opening of the cervix. Having compared all these factors, the specialist names the gestational age of the baby as accurately as possible, and based on this, the due date is calculated.

Another effective method of calculating the onset of labor is an examination by a gynecologist. This method provides relatively accurate information if you consult a specialist in the early stages of pregnancy.

Gynecological specialists often determine the date of expected birth based on menstruation. They use Nägel's formula for this. To use this method of calculation, the doctor must ask the expectant mother whether she regularly has periods or not.

If the answer is negative, the specialist must use other methods of calculating the date of onset of labor, otherwise inaccuracy may be made, which will lead to the onset of labor outside the hospital or the woman’s stay in the maternity hospital for too long.

Other methods can be used as additional ones to calculate the day of birth as accurately as possible.

Why are the results of establishing PDR considered approximate?

According to statistics, only 5% of mothers give birth to babies on the date they calculated or were told by a specialist. No method has been developed that will allow one to determine the exact day of birth. Each method has an error of 3-5 days and even two weeks.

An ultrasound may also be inaccurate if the baby is in an awkward position in the uterus. Deviations in timing are also caused by multiple pregnancies. In this case, several factors are compared in order to at least approximately understand when the birth of children will take place.

The following factors influence the baby's birth date:

age of the expectant mother;
pathologies that a woman suffered during pregnancy or chronic diseases that arose before pregnancy;
location of the placenta;
environmental situation in the region of residence;
state of the nervous system;
harmful addictions;
baby size and multiple pregnancy;
child's development level;
repeat pregnancy;
heredity.

The main point that influences the onset of labor is the course of pregnancy. If there are no complications, labor may begin several days earlier or later than the expected due date. The discrepancy is usually from 3 to 5 days.

Conclusion

How to calculate the due date as accurately as possible? Unfortunately, even a specialist can only give an approximate date for the baby’s birth. But such data is usually enough to mentally prepare for childbirth and prepare everything necessary for the baby for this day.

Online services have appeared on the Internet in which women are asked to enter some information and find out the date of birth. This method is also only an estimate and is not recommended to be relied upon with 100% certainty.

How to find out your due date? About the method for calculating the due date

For calculating the expected date of birth Obstetricians and gynecologists have a very convenient and simple formula: add 9 months and 7 days to the date of the first day of the last menstruation. Or you can calculate even simpler - count back 3 months from the first day of your last menstruation and add 7 to the resulting number.

Estimated date of birth = date of the first day of the last menstrual period + 9 months + 7 days.

Estimated date of birth = date of the first day of the last menstruation – 3 months + 7 days.

But these periods are typical for the average woman with an average 28-day menstrual cycle and ovulation on the 14th–15th day of the cycle.

The average pregnancy lasts 266 days (38 weeks) from the date of conception, or 280 days (40 weeks) if counted from the first day of the last menstrual period. If the expectant mother’s menstrual cycle is shorter or longer than the average 28 days, or ovulation did not occur on the 14th–15th day of the cycle, then the pregnancy may also be longer or shorter. Therefore, it is generally accepted that 280 days is the approximate number of days of pregnancy and the baby can be born between the 266th and 294th day (38–42nd week) of pregnancy.

Calculation of due date based on the day of conception is not an accurate method for determining due date. Even if you know exactly the day on which sexual intercourse occurred, this does not mean that it was on this day that conception occurred, since sperm can remain active in the vagina for up to several days.

How else can you determine the gestational age and calculate the due date?

Determining gestational age using ultrasound

In the early stages, up to 12 weeks of pregnancy, the date of birth can be calculated quite accurately using ultrasound. Over long periods of time this is often difficult due to the fact that each child grows at his own pace. Namely, such indicators as the sizes of different parts of the fetal body are the basis for calculating the gestational age.

Determining the gestational age during a gynecological examination

During pregnancy, the uterus begins to gradually increase in size and acquires a spherical shape. During a gynecological examination before 12 weeks, the doctor can determine the approximate gestational age based on the size of the uterus. At periods of more than 16 weeks, when the uterus extends beyond the womb, the period can be determined by the height of the uterine fundus during examination of the abdomen. Naturally, this method of determining gestational age is not accurate.

Determining the gestational age by the baby's first movement

Another auxiliary method for determining the gestational age and calculating the due date is by movement. Despite the fact that the child begins to make movements quite early, the mother can only feel them when the baby reaches a certain weight. This usually happens in primiparous women at 18-20 weeks of pregnancy, and in multiparous women 2 weeks earlier. However, some women claim that they feel movements as early as 14 weeks and sometimes earlier.

Using all of the above methods, you can more or less accurately determine the gestational age, but the due date will still be approximate. This means that the probability of giving birth on your due date +/- 3 days is about 70%. Do not forget that the date of birth is also influenced by the child’s readiness for extrauterine life. Some children can reach so-called morpho-functional maturity at the 38th week, while others at the 41st.