Day of birth on the day of conception. How to determine the date of birth: ways. The most important weeks of pregnancy

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

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

Growth and development of the fetus. It is important for a doctor who observes the course of pregnancy to know how the developing baby corresponds in size to the gestational age (which is calculated based on the expected date of birth) in order to promptly diagnose such a serious complication as intrauterine growth retardation (IUGR), which is a consequence of placental insufficiency (a pathology in which the placenta inadequately performs the functions of providing the fetus with everything necessary for growth and development). Timely adequate diagnosis and, consequently, the 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 certain complications may develop at various stages of pregnancy, and therefore the terms are determined in which it is necessary to carry out diagnostic measures to identify complications, their prevention and treatment (for example, prenatal screening - the diagnosis of congenital malformations of the fetus - should be carried out at clearly established terms of pregnancy, and if these terms are not observed, its diagnostic value sharply decreases). In diseases such as diabetes mellitus and hypertension, for example, if the course of the disease worsens or treatment does not give a positive effect, it may be necessary to deliver before the spontaneous onset of labor. 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 necessary amount of examination and preparation for delivery, and too early hospitalization is not advisable, since a long stay of a future mother in a hospital can lead to an increased level of anxiety, stress on the eve of childbirth. Terms of antenatal hospitalization for various complications during pregnancy may vary. For example, with diabetes, it is necessary to hospitalize a pregnant woman no later than 36 weeks. With the 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 processes of preparing the body for childbirth begin, which is very dangerous due to prenatal rupture of amniotic fluid in the case of a transverse position of the fetus and the development of bleeding with placenta previa). 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 complete examination, choose the method of delivery, and prevent pregnancy from being overdue.

How to calculate due date

For determining estimated date of birth several methods are used.

obstetric term(according to the date of the last menstruation). It is generally accepted to consider the date of the reference of the menstrual cycle as the date of the first day of the last menstruation - that is, the full menstrual cycle is calculated as the interval from the first day of menstruation to the first day of the next menstruation.

For calculation estimated date of birth By the date of menstruation, there are two ways:

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

Negele formula: 3 months are subtracted from the first day of the last menstruation 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 expected date of birth according to the date of menstruation (we will assume that on February 17 the gestation period will be a full 40 weeks, and therefore, labor should begin around this time).

Embryonic term(by date of conception or ovulation). The probability of pregnancy is maximum on the day when ovulation occurs - the process of 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).

Considering that the egg is capable of fertilization within 24 hours after ovulation, and the lifespan of the 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 the 9-10th day of the menstrual cycle (with a 28-day cycle). This circumstance greatly complicates the establishment of the expected date of birth by the date of conception. It is possible to set the due date for conception in cases where a woman knows exactly the date of ovulation (for example, she monitored basal temperature or, for medical reasons, ultrasonic monitoring of folliculogenesis, the process of egg maturation, was carried out). To determine the PDR, 266 days are added to the date of conception (since this is the true duration of pregnancy) or 38 weeks.

With a regular menstrual cycle (lasting 28 days), there is no difference between the 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 date of first appearance in women's consultation. 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 verify the fact of pregnancy and establish its duration, the doctor will examine the 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 texture).

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 chicken egg, at 7-8 weeks - with a goose egg, by 12 weeks it reaches the size of a newborn's head and its bottom (the so-called upper part of the uterus) can already be palpated (palpated) through the anterior abdominal wall without resorting to vaginal examination. Starting from the second trimester, according to the height of the uterine fundus, one can roughly determine the gestational age: by 16 weeks, the uterine fundus is in the middle of the distance between the womb and the navel, by 24 weeks - at the level of the navel.

It is important to remember that the longer the gestational age, the higher the error in its determination by this parameter can be, since the height of the uterine fundus depends on many individual characteristics: the number of births in history, the size of the fetus, gynecological diseases (for example, with uterine myoma, the size of this organ will be more than normal for a given period), the anatomical features of the body of the expectant mother, etc. Therefore, the examination performed before 12 weeks of pregnancy is of the greatest importance for determining the PDR by attending the antenatal clinic - then the doctor will be able to determine the gestational age by the size of the uterus.

According to ultrasound. Determination of gestational age and estimated date of birth 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 possible time (and it is possible to see the fetal egg 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 fetal egg and the coccyx-parietal size of the CTE of the unborn child are measured. For each gestational age, there are certain KTR standards, measured in millimeters, by comparing which with the data obtained, it is possible to accurately determine the expected date of birth.

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

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

It should be noted that this method DA definitions It is considered additional, or auxiliary, since fetal movements are a very subjective sensation, and besides, expectant mothers do not always celebrate it for the first time in the above terms. For example, primiparous women may first feel fetal movements later in 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 it. Women with a pronounced layer of subcutaneous fat may first feel fetal movements 1-2 weeks later. Multiparous women, on the contrary, can notice the first movements at an earlier date (at 16-17 weeks), as they already know how it happens. These circumstances may reduce the accuracy of determining the expected date of delivery by the date of the first movement of the fetus.

For what calculate the DA in multiple settings?

The need to calculate estimated date of birth by several methods simultaneously due to the following factors. First, despite the availability of state-of-the-art methods for estimating gestational age, it is almost impossible to predict when a woman will go into labor (to the nearest day). Secondly, some of the data used to calculate the estimated date of birth may be uninformative for various reasons. For example, with an irregular menstrual cycle, the calculation of the EDD by the date of the last menstruation will not be accurate, and with a late first appearance at the antenatal clinic, the presence of gynecological diseases (uterine fibroids) or overweight, it will be difficult to determine the gestational age by the size of the uterus. Given these circumstances, the doctor sets the expected date of birth according to the maximum amount of data to clarify the time interval in which the birth is most likely to begin. As a result estimated due date most often defined not as one specific number (for example, January 15), but as a time period (for example, from January 12 to 17).

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

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

Thus, on duration of pregnancy and the date of delivery are influenced by many factors, among which an important role is played by the characteristics of the anamnesis - 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 childbirth also influence the course of this pregnancy. For example, with multiple pregnancies, childbirth often begins earlier than with a single pregnancy, and the gestation period is inversely proportional to the number of fetuses (the more fetuses, the shorter the term), which is due to overstretching of the uterus. With the development of placental insufficiency (a pathology of the course of pregnancy, in which one or more functions of the placenta are disturbed, leading to insufficient supply of the fetus with everything necessary for growth and development), both the early development of labor and an increase in the duration of pregnancy by 1-2 weeks are possible.

Despite the impossibility of absolutely accurately determining the date of birth, it is still necessary to correctly calculate the EDD. Focusing on the expected term of childbirth, the degree of biological readiness of the body of the expectant mother for childbirth (determined by the doctor according to a number of signs, one of the main ones 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 condition of the 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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Pregnancy- a period of change in a woman's life. How many new things she has to learn about herself and her body, about children and even about medicine. How many new terms she will hear! PDR and the pregnancy calendar are one of them. In this article, we will look at what it is.

Everyone knows that pregnancy lasts 9 months. However, having become pregnant, the expectant mother discovers that the term is measured not in months, but in weeks, and there are 40 of them, that is, almost 10 months. Moreover, the child is considered full-term from 38 weeks. The pregnancy calendar is a list of changes that occur with the body of the expectant mother and with her baby for each week of gestation. The term itself is divided into three periods, called trimesters. Let's consider each of them.

First trimester of pregnancy

It lasts from the first to the thirteenth week pregnancy included. This is the most important (if one can “compete” in importance here) and dangerous period. The greatest number of miscarriages occurs during this period, so the expectant mother needs to carefully monitor her health.

In the first three months of pregnancy, the egg is fertilized, then it attaches to the uterus (implantation, i.e. the actual onset of pregnancy) and the formation of the fetus. Initially, the embryo does not look like a person at all: it is just a small ball.

By the end of the first month, the size of the embryo is only 4 mm. It's about the size of a grain of rice. And yet, his internal organs are already forming: the neural tube, the heart, the genital gonads. On the 21st day of pregnancy, with the help of ultrasound, you can hear the heartbeat of a little man: 110-130 beats per minute.

On the 4th-5th weeks there is an active development of the brain. The head takes up a third of the total size.

Between the 7th and 8th weeks, the embryo develops into a fetus. There is separation of the fingers and toes. And from the 8th week it is officially called the fetus.

At 8-9 weeks, all facial features are already distinguishable, the genitals, intestines are formed, fingers appear on the hands.

At 10-12 weeks, the baby begins to move, but the mother does not feel it yet, nails appear on the fingers, and the rudiments of teeth appear in the gums. The heart is fully formed, and the endocrine system begins to produce hormones.

In the first trimester of pregnancy, the expectant mother may experience toxicosis: nausea, sweating, increased salivation, itching of the skin, etc. This is a rather difficult period in the life of both the child and the mother. The mother-placenta-fetus relationship is formed. There is a real hormonal storm in a woman's body!

At about 11-13 weeks, the doctor prescribes the first screening test, which consists of a blood test and ultrasound. It is during this period that it is possible to determine the presence of such genetic diseases as Down syndrome, Edwards, Patau, de Lange, Smith-Opitz.

Second trimester of pregnancy

This is the period from the fourteenth to the twenty-seventh week bearing a child. This is the most fertile time of pregnancy: the first fears and anxieties are over, toxicosis has already ended, but at the same time, the tummy is not too big and does not constrain mom in activities. Enjoy!

During this period, there is an active growth and development of the child. If at the beginning of the second trimester the child was only 10 cm with a weight of 30 g, then by the end it is already as much as 1.2 kg with a height of 35 cm!

The child is actively moving. He explores himself: touches his face with his hands, sucks his fingers, plays with the umbilical cord. Most of the time it is upside down, but it can also turn over. From about 18-22 weeks, a woman begins to feel these movements. The primiparous mother feels them later, around the 20th week, and the "experienced" mother - a little earlier: at the 18th week.

A thin fluff appears above the upper lip, on the eyebrows and on the head. This is latungo. It is designed to keep the original lubricant on the baby's body.

During this period, the tummy begins to grow noticeably. Your old clothes become tight and it's time to replenish your wardrobe with "pregnant" clothes. Pay attention to special tights for pregnant women, trousers, dresses and tunics. In addition, your doctor may prescribe that you wear a support bandage.

At 16-18 weeks, you will need to undergo a second trimester screening. It includes an ultrasound and a blood test (the so-called "triple" test for the level of human chorionic gonadotropin, alpha-fetoprotein and estriol). This allows you to identify malformations and chromosomal abnormalities of the fetus.

Third trimester of pregnancy

This is the period from the 28th week of pregnancy until the birth itself. Finish line. The period of the final formation of the child. At this time, there is a risk of premature birth and late toxicosis (gestosis). Pregnancy is considered mature from the 38th week. Those. if the birth has occurred since the first day of the 38th week, then the child is considered full-term.

This is the period of the final formation of the child: nails grow to the fingertips, permanent teeth are formed under the milk teeth. The child begins to hear and distinguish voices. Now he knows his mother's voice and prefers it to all others after birth.

The movements of the baby are more and more clear. He pushes and kicks, and now not only you can feel it, but also any person who puts his hand to your stomach. By the end of the gestation period, the child becomes so large that it is already difficult for him to perform somersaults and he remains in one position. Most children turn their heads to the lower abdomen. This is called head presentation. If the child lies down with his feet or buttocks, then this is a breech presentation.

In the third trimester, the body of the expectant mother begins to prepare for childbirth. The cervix becomes more elastic, colostrum can be released from the breast.

It becomes difficult to move because of the grown belly. For the same reason, heartburn may begin and hemorrhoids will be found.

During this period, it is better to prepare all the necessary things for the hospital and for the baby.

How to calculate the due date: weekly pregnancy calendar

Having examined in detail the stages of the formation and development of a child in the womb, we came to the concept of PDR, that is, the expected date of birth. From the name it is clear that this is the expected date of birth of the baby. There are several ways to determine it, which will be discussed below. However, it is worth noting that only 17% of children are born on the date of the due date. The remaining 83%, that is, the absolute majority, are born "around" the DA (if we do not talk about emergency unplanned or premature births).

Determination of the term by the date of conception

If the pregnancy was planned, then, usually, the exact date of the sexual intercourse that led to it is known. To this date, 280 days are added (i.e. 40 weeks) and thus the DA is determined. This method is the most accurate, but not one hundred percent (as, in fact, no other). Deviations can be within 1-3 days, since fertilization itself can occur not directly on the day of sexual intercourse, but within a few days after it.

Determination of the period by the date of menstruation

This is the most commonly used method in obstetrics for determining the PDR. It was proposed by the German obstetrician Negele. The calculations are as follows: three months are subtracted from the first day of the last menstruation and 7 days are added. That is, if the last menstruation began, for example, on June 1, subtract 3 months (March, April, May), add 7 days and get the EDD on March 8.

Determination of the term by the date of ovulation

Another way to calculate the estimated date of birth is to calculate by the date of ovulation. 280 days are added to this date and the DA is obtained. However, the complexity of this method lies in the fact that not all women follow their cycle and even more so do not know their ovulation schedule. If you are attentive to your health, then this method can help you find out the date of birth of your child.

Ultrasound calculation accuracy

The date of delivery is also determined at the first mandatory ultrasound, during the screening of the first trimester. It must be completed at 8-11 weeks. During this period, the doctor determines the compliance of the size of the child with the expected gestational age and determines the PDR. This method is the most accurate. However, no method provides an absolute guarantee. In addition, doctors prefer to combine several methods to determine the date of birth.

How to calculate the sex of the child: weekly pregnancy calendar

"Who are you waiting for: a boy or a girl?" - this is the most asked question of a pregnant woman. Disputes about the sex of the baby often begin even before conception and do not stop until the very birth. And since this is such an important question, we decided to look at several ways to find the answer to this question.

Determination by blood group

This method can be divided into several subspecies.

Determination by blood group. You need to know the blood type of mom and dad and see the result in the table. The reliability of this method is very doubtful, because in practice children of different sexes are quite often found in the same family.

According to the Rh factor. He matters too. If it is the same for both parents, then there will be a boy, and if it is different. That is possible options. This method is also unreliable. In addition, it can produce the opposite result with the previous one.

For the renewal of the blood. Its essence lies in the fact that the blood of a man and a woman is renewed at different rates: for women every 3 years, and for men every 4. Whose blood will be “younger” at the time of conception, the child will be born of this gender. To do this, the age of the mother is divided by 3, and the father, respectively, by 4. But it is also worth considering large blood loss: donation (both blood donation and transfusion), operations, abortions, injuries. Those. should be counted from the date of the last blood loss.

Let's look at an example. Let the expectant mother at the time of conception be 26 years old, and the father - 29. Divide 26 by 3, we get 8.7 and 29 by 4, we get 7.3. We analyze the numbers after the comma: 7 for mom and 3 for dad. It turns out that the father's blood was renewed quite recently, that is, the parents, most likely, will be waiting for the boy.

Determination of the sex of the unborn child using ultrasound

This is the most reliable of the publicly available methods. However, its veracity directly depends on the timing of the study and the experience of the doctor. Until the 8th week of pregnancy, the baby does not have a gender. The process of formation of the genitals ends by about 10-12 weeks.

But doctors recommend performing an ultrasound to determine the sex no earlier than the 15th week. However, most often everything is found out during the screening of the second trimester (22-25 weeks of pregnancy). On the monitor, the doctor should visualize the scrotum and penis, if the child is male, and the labia majora, if female. Sometimes the loops of the umbilical cord or the fingers of the fetal hand are mistaken for the penis, and in utero girls there is a swelling of the labia that passes over time, which are mistaken for the scrotum.

Definition by the appearance of a pregnant woman

One of the most controversial and even playful ways, which, nevertheless, sometimes gives a result. What is called, "not thanks to, but in spite of." It is popularly believed that if the stomach sticks out like a ball, then a boy is sitting there, and if it is flatter, neater, then a girl.

However, the shape of the abdomen is influenced by two factors: the size of the baby and its intrauterine position. Yes, indeed, boys are often larger than girls, but not so much that it affects the size of the abdomen. Well, the intrauterine position does not depend on gender at all and can change throughout pregnancy.

Sex determination by folk methods

Folk methods have been passed down from generation to generation since the days when there was no ultrasound. What our great-grandmothers and grandmothers did not think of! Now all this seems more like an anecdote than a real way to find out the gender of the child, but still let's talk about them. As they say, a moment of positive.

• Wedding ring method. You should hang the wedding ring on a thread above the hand or stomach of the expectant mother. If it starts spinning in a circle - wait for a girl, if from side to side - a boy. Instead of a ring, you can use a needle or nut.
• Divination with a key. You need to find a round key, with a round head and a long leg, and put it in front of the pregnant woman. If she took him by the head - to the girl, if by the leg - to the boy, if in the middle - to the twins.

A few more clues:

• If during pregnancy the future father is gaining weight along with his wife - to the boy, if the woman has recovered in the hip area - to the girl.
• If the expectant mother began to look worse (pimples or age spots appeared on her face, redness), it means that the girl, as it were, “takes away beauty”. If the pregnant woman looks great for all months, expect a boy.
• If there is a boy in the stomach, then it draws on sour, salty, meat and milk; if a girl, then she is drawn to sweet and fruity.
• Expectant mothers of boys have an increased appetite throughout pregnancy, and mothers of girls feel sick, especially in the first trimester.

Chinese pregnancy calendar: How to calculate the gender of the baby

It is a table, which, according to legend, was found in one of the burials in ancient China. Shows the relationship of the sex of the child with the age of the mother and the month of conception.

Japanese baby gender calendar

Japanese calendar based on the relationship of the sex of the child and the months of birth of the parents and the month of conception. In the first table, find the number at the intersection of the months of birth of the mother and father. Then, in the second table, find the column at the top of which is this number. It indicates the months of conception, and opposite each month is the probability of the birth of a boy or girl, expressed by the number of crosses. The more crosses, the higher the likelihood of conceiving a child of one sex or another.

All pregnant women know modern ways to calculate the due date. The approximate date of birth of the child can be found out (calculated) and checked in advance.

For every expectant mother during pregnancy, the most important thing is not her birthday, but the date of birth, which can be calculated today with a small error.

There are several different ways, methods, techniques, how to find out the date of birth. They are based on the well-known physiological features of the course of pregnancy. It is known, in particular, that on average, a normal pregnancy lasts about 40 weeks, if we count from the beginning of the last menstruation. Absolutely accurately calculate the date of birth, of course, is impossible. The duration of pregnancy is different for all women. But all pregnant women know how to correctly calculate the expected date of birth. The error is most often a few days.

Methods and methods of calculation

How to calculate due date? It is possible, for example, to determine the date of birth by the date of conception, if there is reason to more or less accurately assume on which day it happened. From the date of conception, respectively, just count the duration of pregnancy.

What is a DA, what is an “online calculator”?

EDD is the expected date of birth. In order to determine it, you can, among other things, use the so-called "calculators", which are also available online today. Each such service on the Internet has instructions on how to determine the gestational age, how to calculate the date of birth (DDR) for the last menstruation. You can do this in just a few seconds.

Definition of the DA

You can calculate the expected date of birth not only with the help of a calculator on the Internet, but also on your own. There are several ways. All of them have an error, but with a competent calculation, it is possible to calculate the estimated date of birth with an accuracy of up to a week.

Does the date of delivery depend on the characteristics of the menstrual cycle?

The date of birth can be determined by the last menstrual period. Calculating childbirth by menstruation (determining the due date by the date of conception) is quite simple.

To calculate the gestational age, and use it to determine the date of birth, you need to remember the day the last menstruation began. It is this date that is taken as the basis. From the date it is necessary to count exactly 3 months ago, add another 7 days to the resulting day. This will be the date when, most likely, there will be a beginning of a new life. If, for example, the last menstruation began on October 24, then you need to count back 3 months - it will be July 24, plus 7 days - it will be July 31. This is exactly the term of childbirth, calculated according to the last menstruation.

The duration of the menstrual cycle (MC) of a woman is important in determining the PDR. If the MC exceeds the usual 4 weeks, then the pregnancy lasts more than 40 weeks, and vice versa. But the error in this case is no more than 5 days.

Methods for determining the EDD by ovulation

Calculation of due date can be done in different ways. You can determine the date of birth not only by the last menstruation. It is easier to make a special weekly pregnancy calendar. But for this you need to know when fertilization occurred. And how to find out the date of conception?

First you need to remember how the process of fertilization proceeds. After menstruation, vesicles form in the ovary, in one of which a female cell appears. She breaks through the follicle and is released. Her path lies in the direction of the uterus. In this sexual path, under favorable circumstances, the spermatozoon fertilizes the egg. This is precisely the very favorable moment that you need to know in order to calculate the time of birth according to the day of conception. The fertilized egg continues to move towards the uterus, and its path can end only 7 days after meeting with the sperm. After that, there are changes in the structure of the mammary glands, the first signs of pregnancy appear.

Calculation of the ovulation calendar

If a woman does not know the exact day of ovulation, it can be determined based on her cycle readings. To calculate the date of birth by ovulation, you need to take into account several parameters:

• cycle length over the past few months;
• systematic;
• duration and characteristics of menstruation.

Normally, menstrual cycles should be equal in duration, not have significant differences in start and end times, and in the nature of the course. If all these parameters are normal, then it will not be difficult to calculate the date of conception and draw up a labor schedule. The date of birth, calculated from the last menstruation, will be more or less accurate.

Irregular cycle ovulation calculator

If the MC is not regular, then it will be more difficult to detect ovulation (and, accordingly, calculate the date of birth from the date of conception), but still possible. When calculating by the date of the last menstruation, the size of the error increases, since the result depends on the length of the cycle, which is always different. But in this case, it is also possible to calculate the date of birth by menstruation (according to the menstrual cycle).

Weekly pregnancy and child development calendar

After performing the necessary calculations, the woman receives a specific date when childbirth can occur. There are many services that not only give an answer to the question “how to calculate the date of birth”, but also help to create a child development calendar. Such a weekly pregnancy calendar, in fact, allows a woman to draw up a specific action plan for the entire period of pregnancy.

Negele formula

The calculation of the term of childbirth is done according to the Negele formula. To do this, a woman needs to know the exact day when the last menstruation before pregnancy began. Many women do not remember this day. Therefore, gynecologists recommend marking the first day of menstruation on the calendar to make it easier to calculate the date of birth by conception, especially if it was random.

In what week can childbirth occur?

If you correctly calculate the approximate date of delivery, then you can make a mistake in specific days, but, as a rule, you can more or less accurately determine the week when the birth will occur. Due date "plus or minus a week" is calculated with higher accuracy.

Determination of PDR using ultrasound

Determining the date of birth using ultrasound today is considered a reliable way. If its results coincide with those calculated on the last monthly date of birth, then the probability of such a forecast will be above 90%.

When is the best time to do an ultrasound?

To calculate the date of birth by ultrasound, you must contact the clinic. It must be remembered that the gestational age at which the examination is carried out is taken into account. If it is carried out at 11-14 weeks, then the error in determining the term of delivery will be 1-3 days. In the first trimester of development, embryos almost do not differ in size. In the second trimester, the weight and size of the fetus already have more significant differences, and in the third they become even more pronounced. Therefore, it becomes easier to find out the due date.

The value of an accurate calculation of gestational age

Gestation is actually pregnancy. The difference between these two concepts lies in the fact that the gestation period is calculated as the number of full weeks of the entire period while a woman is carrying a child. The onset of gestation is counted from the calendar date of the start of the last menstrual cycle. Those. the concept of gestation makes it possible to more accurately calculate the approximate date of birth. The child is likely to be born at the time that the woman calculated based on the gestational age.

Method of "first stirring"

You can calculate the date of birth by the first movement of the baby during pregnancy. If you felt the baby move, how to calculate the estimated due date? Women during their first pregnancy feel fetal movement at the 20th week of pregnancy (that is, exactly at half the term). In the second and subsequent pregnancies, the first movement may occur at the 18th week. Accordingly, to calculate when the baby is born, you need to add 22 weeks. But it must be borne in mind that this method today is considered not the most reliable. But gynecologists, when they do weight measurements and other procedures, ask the woman and the day of the first stirring of the child.

Signs of close birth

In the last weeks before childbirth, some signs begin to appear that may indicate the approach of childbirth. At this time, it is easier to calculate the day of childbirth, and the woman should be prepared for the fact that this will begin soon. With the help of a calculator, you can calculate how many days are approximately left until delivery. And then, by the date of birth, calculate the gestational age.

Signs:

1. The belly goes down.
2. Appetite is constantly changing, a woman is losing weight. There is an upset stomach, the woman goes to the toilet very often.
3. Mood swings in a woman are becoming stronger and more frequent. During this period, the expectant mother constantly wants to retire.
4. Shortness of breath and heartburn disappear. During most of her pregnancy, a woman feels that the fetus continues to press on the mother's internal organs. And before childbirth it disappears.
5. The baby in the stomach behaves much calmer and quieter.
6. There are pulling pains below, in the pubic bone.
7. Mucous discharge from the vagina appears.

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How the body of women changes by week

In the images you can see a rough illustration of the development of the baby inside the womb for each week. To the left of the images is a summary of the fetal growth for that week. For more complete and detailed information, you can find by clicking on the "More" link, which is located under each description.

Weekly pregnancy calendar is very handy.

Knowing how pregnancy goes by week is not only interesting, but also very useful! The pregnancy calendar will help you with this. It is designed to keep the mother informed of all the events of intrauterine development, to help adjust nutrition and lifestyle during different periods of pregnancy. In addition, the pregnancy calendar allows you to calculate the expected date of birth.

Weekly pregnancy calendar

It will facilitate medical supervision of the expectant mother and her baby, and will also give answers to the most important questions that you will certainly face: when the stomach begins to grow, why it makes you feel sick during pregnancy, how to recognize the first fetal movement.

Thanks to this calendar, you will not forget that the time has come to undergo screening, take tests, go for a scheduled ultrasound. And with the approaching date of childbirth, such a weekly calendar will help you prepare in the best way for the long-awaited event.

This pregnancy calculator will allow you to calculate how long you are now, the date of future birth, the date of conception, and even the zodiac sign of the future baby and his zodiac animal according to the eastern calendar. You can also determine the age of the fetus, its weight and height, and how much time is left before delivery. To do this, you need to enter the date of the first day of your last period and the length of your menstrual cycle. In addition, our calculator generates a very convenient and practical weekly pregnancy table. Using it, you can navigate which week of pregnancy you are currently in, as well as track the height and weight of your unborn child.

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Monthly pregnancy calendar.

By month

Monthly pregnancy calendar will be your guide for all 40 weeks of pregnancy. Each expectant mother will be able to leave her feedback, observations, share experiences and useful information here. Together we will monitor how quickly our kids grow and develop! And give advice on the right way of life, the way of eating and the safe treatment of all sorts of ailments.

Every month of pregnancy is characterized by serious changes in the development of the child: he achieves more and more success in physical and mental development, the baby’s brain grows intensively, muscle mass grows stronger, vital organs and systems are formed, and even the first natural skills! The pregnancy calendar by month will acquaint you in detail with these events at each stage.

Personal pregnancy calendar

Every woman can keep a personal pregnancy calendar. Moreover, it is welcome and recommended. You are in a very special state right now. Many sensations are new to you, and can even cause excitement and fear - the body of a pregnant woman undergoes tremendous changes, both in a physiological sense and in a psychological one.

The weekly and monthly pregnancy calendar has been compiled with an attempt and purpose to explain each of them.

You can have a personal pregnancy calendar in a separate notebook, which you will decorate in accordance with your mood, tastes, feelings, as well as who you expect: a boy or a girl. Such an album will be a great start to a family chronicle or a chronicle of the life of your heir.

Interactive pregnancy calendar

But in addition, modern expectant mothers resort to the services of the Internet and choose an interactive pregnancy calendar for observation. It's convenient, easy to use, accurate, practical, informative, and completely free!

You can resort to its help when you need to quickly determine the date of birth or accurately determine the current gestational age (using a special calculator for this), divide your pregnancy into trimesters, months or weeks.

Online pregnancy calendar is becoming more and more popular. Women want to know more about this special period: what are the first signs of pregnancy, how to avoid miscarriage, what to do with increased uterine tone, how to find out the first harbingers of childbirth, how to determine the sex of the child. The calendar contains articles, tips, explanations, and a calculator for determining the duration of pregnancy and the expected date of delivery.

You can conduct personal monitoring of your own pregnancy, your condition and that of your child, and carry out the calculations that interest you.

Online pregnancy calendar - at your service! Keep your finger on the pulse of the most important events in your life!

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How to correctly calculate the gestational age by weeks and days

Obstetrician-gynecologists start counting the gestational age from the first day of the last menstruation. Usually, the actual period is 13-16 days less, since conception occurs approximately in the middle of the menstrual cycle, i.e. at the time of ovulation. However, to avoid confusion, doctors start counting the gestational age 2 weeks before the date of conception.

In medicine, there is a term applied to the timing of pregnancy - the expected date of birth (PDR). When expectant mothers come for the first pregnancy examination to the antenatal clinic and are registered, the doctor makes calculations and tells the woman the approximate day of delivery.

It focuses on the date of the last menstruation, which every woman needs to know. The gynecologist will definitely ask the patient if they started and how long they lasted.

If the expectant mother's menstrual cycle is regular (once every 28 days), the doctor adds 14 days to the start of menstruation and gets the approximate date of conception. The maturation and release of the female egg, that is, ovulation, occurs precisely at this time.

Women need to mark the exact dates of the onset of menstruation on a desktop or small calendar all the time, this can be useful both during pregnancy and any visit to a gynecologist for advice.

Spermatozoa can fertilize an egg immediately on the day of ovulation, or maybe after 1-3 days. Therefore, the exact date of conception today can only be said by a doctor doing an ultrasound scan.

If the pregnancy lasts no more than 12 weeks, the doctor can quite accurately name the date of conception. At a later date, this is more difficult to do. Therefore, it is important for the expectant mother to undergo an ultrasound scan in the first weeks of pregnancy.

After an ultrasound examination, the doctor will add 28 weeks or 266 days to the figure in the colleague's report, plus another 14 days that have passed from the last date of the start of menstruation to ovulation, and receive a check figure. She is reported to the pregnant woman as the date of the long-awaited event.

The birth of a baby is always a joy, but this joy appears under different circumstances. A child may be born before the term named by the doctor, or it may linger in the mother's stomach for various reasons.

The fetus is not born by women who have suffered severe infections or who suffer from endocrine diseases.

A full-term pregnancy is considered between 38 and 42 weeks. If a woman walks for more than 42 weeks, then this is a post-term pregnancy. The timing can be influenced by the health of the mother, her nutrition and environment, as well as the characteristics of the intrauterine development of the child.

To calculate the date of birth, the well-known Negele formula is also used. According to her, to the last date of the beginning of menstruation, you need to add 9 months and then add another 7 days.

By the day of the first movement of the fetus, you can also approximately calculate the date of birth of the child. You need to add 20 weeks to it if the pregnancy is the first and 18 weeks if the second. The error will be about 2 weeks, which is quite a lot compared to the date given after the ultrasound, for example.

So the expectant mother can calculate the date of birth on her own, but it will still be expected, as obstetricians and gynecologists say. Doctors advise not to worry more about the exact day when the baby will be born, but about how to successfully bear the child.

A healthy, optimistic mother will give birth well a day earlier and a few days later. The main thing is to have time to prepare for the desired event on time, and even the approximate date of birth will help this.