As the date of birth is considered. Calculation of the due date. How the body of women changes by week

It is useful for a woman who is going to become a mother to learn how to calculate the approximate date of birth by the known date of the last menstruation. These calculations, of course, will not be absolutely accurate, but knowing even the estimated moment of childbirth will allow you to calmly prepare for the upcoming process.

Calmness and poise are very valuable qualities for a pregnant woman, they should be armed and guided from the first to the last gestational week. The following material is about how the date of birth is calculated by the last month.

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Based on the average duration of pregnancy (40 weeks), it is not difficult to calculate the date of birth by the last menstrual period. For this, 40 weeks ahead of the calendar are counted from the start date of menstruation.

In world obstetric practice, a quick method is used to calculate the timing of pregnancy and, accordingly, childbirth from this starting point - the date of the last menstruation. The timing of pregnancy determined by this method is called obstetric. They cannot be considered accurate, if only because no one can predict how many weeks a pregnancy will last - 36 or 42.

Obstetric calendar

The starting point in the calculation formula is the first day of the last menstruation:

• from 1 day of the last menstruation, you need to count back 3 months according to the calendar;
• add 7 days to the received date.

1. The last period began on May 6.
2. We count from May 6 3 months ago - we get February 6.
3. We add 7 days to February 6 - we get February 13.
4. The estimated date of birth, as it was possible to calculate by the monthly ones, is February 13th.

This simplest way of calculating is called the Negele formula, and its reliability correlates with the duration of the menstrual cycle. If the cycle is too long or irregular, counting errors are inevitable.

What affects the due date?

Interesting is the opinion of Western experts regarding the myths concerning the influence of certain factors on the date of birth. They conducted a study in which they had urine samples taken daily to measure hormone levels. Thanks to daily monitoring, the fertilization dates were precisely set in the subjects and the duration of gestation was calculated with maximum accuracy. As a result (after childbirth), it turned out that the timing in some cases differed from that calculated for as much as 5 weeks, although the pregnant women were in the same conditions.

The most famous factors influencing the duration of gestation and the date of delivery:

• the duration of the monthly cycles - it is considered that the longer they are, the later the birth will come;
• hereditary predisposition - in families where women overweight children, this feature is passed from generation to generation;
• dynamics of intrauterine development - if the fetus develops "according to plan", gains weight and height on time, the date of birth may coincide with the calculation for the last monthly period.

Experts criticized the myth about the influence of spicy food on the term of labor - if it was calculated by the date of menstruation, and labor does not occur, there is no need to “speed up” them by eating hot spices, as about 20% of pregnant American women do. In this way, they try to increase peristalsis (wave-like contraction of the walls of the stomach or intestines) and provoke uterine contractions, but this method is not scientifically substantiated.

It is also wrong to say that the first birth is usually postponed. Medical research data suggests that the first birth often occurs earlier than the date that the JK could determine by the last menstruation.

The order of delivery does not affect the timeliness of the delivery.

Is it possible to determine exactly and what is the error?

Despite the fact that the Negele formula is considered an approximate way to find out the date of birth by the last menstruation, a considerable number of women on the forums claim that their children were born almost exactly at the time calculated by the doctor +/- 1-2 days. Is it possible, in this case, to consider this calculation method accurate if the statistics indicate only 5% coincidence of the date of birth with the one that was calculated by the date of the last menstruation?

Most doctors generally propose to cancel the indication of the exact date of delivery in order to save future parents from completely unnecessary worries about the "incorrectness" of the onset of true birth. This, according to experts, does not give anything but an extra reason for a stressful situation in the future woman in labor and her relatives.

Studies have shown that under the same conditions of gestation, the time of onset of labor in different women may differ by 5, or even 6 weeks, that is, by 1.5 months.

How to calculate due date in other ways?

If in doubt about the date of the last menstrual period, the due date can be calculated by such methods as ultrasound examination, calculation by gynecological examination, the appearance of the first fetal movements, and others. None of the listed methods guarantee the accuracy of the calculations.

How to find out by ultrasound?

When a woman passes in the early stages of pregnancy (11-12 weeks), the doctor determines the PDD based on the parameters of the fetus:

• the size of the ovum and embryo - visualized as early as 4-5 weeks;
• coccygeal-parietal size (CTE) - the length of the fetus from the head to the coccyx;
• the size of the limbs, head and tummy of the baby, which up to 12 weeks develop approximately the same in all children.

According to these parameters, the gestational age is established, and based on this, the term of delivery can be calculated, taking into account the approximate date of conception (usually 7-14 days from the first day of the last menstruation).

Calculation based on inspection

Surveys when registering a woman after a delay in menstruation also make it possible to calculate the date of birth. In this case, parameters such as (the most reliable) and the size of the uterus, determined during a gynecological examination, are taken into account. This is one of the oldest methods of determining the gestational age at the earliest stage (and, accordingly, childbirth).

By 5 weeks, the uterus softens, rounds and slightly increases in size. This is exactly what it is felt during a two-handed examination, when the obstetrician-gynecologist examines the state of the cervix through the vagina with one hand, and palpates the abdomen with the other, trying to detect an enlarged and rounded uterus.

After 12 weeks, the method for determining the period for examination is not used, since changes in the uterus vary depending on several reasons:

• the structure of the pelvis of the future woman in labor;
• the amount of amniotic fluid in the ovum (and the norm);
• the size of the fetus.

When receiving examination data that differ from the calculations by ultrasound or by the date of the last regulations, preference is given to the latter when recording in the card of the pregnant woman.

Manual examination of a pregnant woman

How to count by the first stir?

It is not recommended today to calculate the PDR based on the appearance of fetal movements. Previously, they considered it simply - by the date when the child first moved, they added 20 weeks and received the estimated date of his birth. Long-term observations have shown the complete inconsistency of this method, since the onset of fetal movements in different women differs markedly:

• some expectant mothers begin to "hear" the baby at 15-16 weeks;
• in others, movements begin after 20 weeks;
• working mothers, who are in constant motion and bustle, may not notice and miss the beginning of the first push;
• future women in labor, sitting at home and listening to every sound inside themselves, can take intestinal peristalsis for movements.

Even mothers who have given birth many times are not immune from imaginary sensations, therefore, it is not advisable to calculate the date of birth by perturbations.

If the date of conception is known, and this is not always possible to find out with high accuracy, calculating the date of onset of labor is as simple as by the date of menstruation. To do this, you just need to count from the day of conception 40 weeks ahead or 3 months ago on the calendar. But this calculation cannot be called absolutely accurate, since the real duration of pregnancy cannot be predicted.

Child development calendar

In anticipation of childbirth, it is interesting to track how the baby develops, how he prepares for birth, according to the calendar of fetal development. The calendar is compiled on the basis of long-term observations of intrauterine development using various diagnostic tools.

Term	Fetal condition
1 trimester	By the age of 2 weeks, the fetus has the size of a grain of sand (0.35-1.00 mm), but is already receiving biochemical support, providing respiration and nutrition from the so-called extraembryonic organs - the amnion, chorion and yolk sac. At 3 weeks, the heart, central nervous system, the rudiments of bones and muscles, ears and eyes are formed, the growth of the embryo is 1.5 mm. 4-8 weeks is the most important and vulnerable period, subject to harmful influences. The nervous system and other organs are actively formed, the heart begins to beat. The weight of the embryo reaches 3 g, the parieto-sacral size is 14-20 mm. At 8 weeks, the period of development is called fetal, and the embryo becomes a fetus. His skin is still transparent, vessels are visible under it. The formation of the external genital organs begins, the tail disappears. At 10 weeks, the fetus already looks like a miniature copy of a human, albeit with a disproportionately large head and small limbs. Growth for the last 3 weeks has almost doubled - up to 60 mm by CTE, weight - 8-14 g.
2 trimester	The features of the baby's face are rapidly taking shape, a "germ fluff" (the basis of future fingerprints) appears, fluff on the brow ridges and on the head. The first taste sensations appear - the fetus reacts to bitter, sour and sweet substances dissolved in the amniotic fluid with swallowing movements. She knows how to yawn, suck her thumb and even somersault, but mom does not feel it yet. When the obstetrician probes the mother's abdomen, the fetus reacts - frowns, turns its head. By the 16th week, the fetus acquires the following parameters: CTE - 108-116 mm, weight - 80-110 g. By the 20th week, the baby's movements become more active and tangible for the mother. He adds 10 g per day in weight, grows in length. At 22 weeks, it weighs 530-600 g, CTE - 21 cm, stores adipose tissue under the skin, becoming plump and less nimble than before.
3 trimester	At 28 weeks, the fetus reacts to external sounds (music, mother's voice, etc.). It trains its lungs by swallowing amniotic fluid and breathing with its chest. His full height (from head to heels) is 38 cm, weight - 1.3 - 1.4 kg. By 30 weeks, wrinkles disappear from the baby's face, there is already a decent "hair" on the head, which becomes proportional to the body, the weight reaches 1.8 kg, and the full height is 42 cm. At 31 weeks, the baby's immune system develops intensively, subcutaneous fat builds up. A surfactant appears in the lungs - a substance that will prevent the baby's lungs from sticking together after childbirth and will ensure their functioning. The baby's weight is approaching 2 kg, full height - up to 43 cm. 34 weeks - growth by leaps and bounds. Most babies by this time turn over in the uterus head down. Weight is approaching 2.75 kg, height - 46 cm. At 36 weeks, pregnancy status is defined as full-term and delivery is expected from day to day. The baby's skin is cleared of vellus hair, the hairline on the head has grown to 1-2 cm, the nails have grown above the fingertips. In the intestines of the baby, meconium accumulates - a black-green substance that is the original feces. After birth, he immediately leaves the child's body. In boys, the testicles have already descended into the scrotum, this will need to be checked immediately after the baby is born. The child's weight reaches 3.1 kg, the height is close to 50 cm.

The child's development calendar shows that calculating the date of birth by menstruation can be very conditional - by 36 weeks the child is ready for birth, but it can remain in the womb for several more weeks. The reasons for the continued stay of the baby in the womb remain a mystery to medicine.

Conclusion

1. It is convenient and easy to calculate the date of birth by the dates of the last menstruation - you need to subtract from the last 3 months and add 7 days.
2. For many women, the dates calculated by the obstetrician coincide with the real dates of childbirth.
3. The starting point in the calculation is the first day of the last menstruation, so it is advisable to remember or write down the timing of their appearance.

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How many women give birth, the same amount of time there is no dispute among expectant mothers about how to determine the date of birth of a child. The difference between your own calculations, the ultrasound readings and the 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 exact way

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

• Obstetric, which is calculated according to the last menstruation.
• Primary fetal movement.
• After visiting the gynecologist, who sets the date based on the examination.
• Fetal, 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 time frame with a special online calculator. With so many different ways of determining pregnancy, doctors calculate with accuracy the baby's birthday according to statistics only in 4 cases out of 100, because many different factors affect the duration of gestation, and heredity is the first thing.

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

Determining the term of labor by menstruation

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

Much more precisely, the term is determined by the Keller formula. If 280 days are added to the first day of the last menstruation, then the approximate birthday of the baby will be released. Where does 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 conception of a child to his birth (266 days);
• average menstrual cycle (28 days);
• ovulation period (14 days 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 by 280 days. The lifespan of a sperm is several days, so even if the time of intercourse is known, it is impossible to determine exactly when ovulation occurred. A baby is considered full-term if it was 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 the due date by the date of conception

It is very easy to determine the moment of birth by the day of ovulation or the date of conception. The body of a healthy woman is able to conceive a child only on certain days of ovulation, when the egg is ripe and leaves the ovary. If the menstrual cycle lasts 28 days, then ovulation happens 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 abundant discharge from the vagina begins, libido increases and the heaviness in the lower abdomen is felt.

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 term of delivery is determined by the day of intercourse, if it was a single one. But here there is a high probability of inaccuracy, since sperm cells live for several days. So, if intercourse was on the 14th day of the cycle, then conception occurred on the 16th or 17th day.

Determination of the term of labor by the first movement of the fetus

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 fetal movement usually marks exactly the middle of pregnancy, therefore, the due date is counted from this date. But experienced obstetricians doubt the accuracy of this method, and they have several reasons for this:

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

For these reasons, the method of determining the child's birthday by the first stirring cannot be called accurate. The error is especially large if the fetus ripens 41 or 42 weeks, which is considered quite normal. So that the doctor and mother do not make the wrong decision in relation to the fetus, there are more accurate ways to determine the duration of pregnancy, for example, an ultrasound examination.

How to find out the date of birth using an ultrasound scan

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

In the later stages, even with the help of an ultrasound scan, it is impossible to determine the exact birthday of the child. After all, everything is individual: some babies are born with a weight of 5 kg, others weigh a little more than 2 kg at birth. Also, studies in the field of obstetrics and gynecology show 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 delivery in any month of pregnancy. In any case, both doctors and expectant mothers believe in the results of ultrasound examinations in the first place.

Date of birth determination table

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 an average of 9 kg to 14. If twins are expected, then the gained weight reaches 21 kg. In the first trimester, the weight practically does not change, in the second, she gains about 1 kg per month, and already in the third trimester, a woman is gaining weight rapidly - up to 500 g in one week.

Guided by a special table for determining the timing of childbirth, by weight, you can check the readings of the numbers during weighing. Obstetricians begin to use this table from the 7th month of pregnancy, when the expectant mother is actively gaining weight. According to the information on 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 in the table according to the following types:

• Lean - up to 19.8 (group 1)
• Medium build - from 19.8 to 26 (group 2)
• Obese - from 26 (group 3)

When girls find out that they are pregnant, the first thing they do is try to remember or calculate the exact date of conception. This happens every time when it comes to a planned or unplanned pregnancy, in the presence of regular sex life. It is clear that everyone wants to know exactly when fertilization took place. Interest is especially intense when the emotional coloring of the long-awaited news begins to lose its intensity and brightness.

If in the first days the expectant mother and father fly on the wings of happiness, then later, when they return to their natural state, they express a desire to find out when their baby or baby will be born. This desire is completely normal. It is due to banal human curiosity and a number of practical goals. Expectant mothers are trying to calculate the date of birth by the date of conception on a calculator, as they are terribly interested in:

• when conception occurred (it is likely that this affects the determination of the child's father);
• in what month to wait for the appearance of the crumbs;
• when to start buying things, clothes for a future family member;
• what name is better to choose, according to the church calendar or astrological laws;
• where and when to plan a family vacation before the birth of a child.

How many life situations, so many different interests in pregnancy. Despite various reasons, information about the upcoming birth worries all responsible mothers, without exception. The very first thing they try to remember is the moment of conception itself. Then convulsively add 9 months. The knowledge that it takes about 9 months to bear a child is completely insufficient. And few people know how to count "roughly nine months":

• From which day to count - the day when sexual intercourse was performed, when there was ovulation, the last menstruation?
• Take calendar months or those that are called conditional (thirty days each)?

As soon as a girl encounters pregnancy for the first time, the period of 9 months seems incredibly long and completely uncertain. Of course, I want to calculate the date of the upcoming birth as concretely as possible. And this is necessary not so much for solving some practical family problems as for timely control over the development of the fetus.

As experts note, recalling the day when sexual intercourse was performed, knowing certain individual characteristics characteristic of the body, it is really possible to determine the day of conception. This is very important for couples who are planning a pregnancy, visit planning centers, consultations, keep menstrual diaries - they approach the birth of a child responsibly and competently.

What to do to those girls who cannot remember the date of conception, who are confused in days, partners and generally don’t remember when the “fateful” sexual intercourse was performed? If you cannot name the exact day when fertilization may have occurred, it will be problematic to calculate the day of the appearance of the crumbs. But, nevertheless, there are several ways to find out the PDD (estimated date of birth).

There are different possibilities for calculating a relatively accurate (or at least an approximate) date of birth:

• own calculations;
• online calculator;
• examination by a gynecologist;

Surprisingly, whichever option you decide to choose, each of them has similar principles and algorithms. Therefore, you can safely start with your own "research", then use a virtual calculator and then confirm the guesses with a competent opinion of the doctor.

Determining the gestational age by the date of conception and ovulation

Many girls use personal conception calendars, which can be used to calculate the approximate time of delivery by the date of conception. Some couples who decide to have a baby try not to miss the most favorable days for fertilization. Therefore, they strictly monitor ovulation, try to have sex on important days. And it is right. When there is an understanding of how conception occurs, the likelihood of a baby being born increases significantly. It is important to understand in detail how the process of childbirth proceeds in the female body:

• after menstruation, bubbles form in the ovary, in one of which a female egg appears;
• it reaches its peak of development and is released, ruptured by the follicle;
• towards the uterus, the cell can be fertilized with a sperm cell, if favorable conditions are created for this (knowing the day of fertilization, it is quite easy to calculate the date of birth by conception);
• after a week (7 days), the fertilized egg is implanted into the uterus;
• inside the uterus, the fetus begins to grow and develop - the unborn child;
• further changes occur in the woman's body: the mammary glands swell under the influence of progesterone.

As soon as the expectant mother realizes that she is in an interesting position, she usually sits down to calculate the expected date of birth, draws up a pregnancy calendar, goes to the clinic for tests and finds out the doctor's advice. You can calculate the date of birth by the date of conception in a few minutes, if you know when you ovulated, if you remember when intercourse was performed.

Difficulties can arise when partners enter into intimate relationships every day. It should be remembered here that fertilization can occur exclusively at the moment the cell is released from the follicle membrane, when it has passed into the genital tract. This process is short-lived, and therefore serious errors in calculating the due date by the date of ovulation are excluded.

Determining the duration of pregnancy by the last menstruation

You can also calculate the day of birth based on your last menstrual period. This method is relevant when the expectant mother does not know the exact day of ovulation. For the calculation, you need to take the readings of your cycle. Take a look at your personal women's calendar and calculate the date of your future birth using data such as:

• Cycle duration. The girl needs to calculate the exact number of days between cycles. It is advisable to analyze the last 5-7 months. A female cycle of 28 days is considered the norm. But on an individual basis, the cycle can vary from 21 to 33 days.
• The regularity of menstruation. Comparing the obtained numbers with each other, you will see that the cycles are approximately equal. Deviations of 1-2 days are allowed. One-off shifts, which are calculated in weeks, represent a deviation from the norm. Such failures are possible due to stress, illness, climate change. Alternatively, they can be caused by the use of hormone-containing drugs. There should be no reason to worry, this happens to many women. When regular shifts of 5 or more days are observed, we are talking about an irregular rhythm. And here it is already worth seeking advice from a gynecologist. Only a doctor can help identify the cause of the problem.
• Duration of menstruation and their characteristics. Discharges of the same type in abundance, duration and structure are considered the norm. Doctors say the length of the menstrual cycle affects the timing of labor. For example, if it is more than 28 standard days, then the pregnancy will be more than 40 weeks. When deviations in one direction or another are more than 5 days, errors are made in the calculations.

If there are certain failures and deviations from the norm, it will be difficult to calculate the date of birth by menstruation. If we are talking about a regular female cycle, lasting, say, 28 days, then you can determine the middle of the cycle: divide 28 by 2. On the 14th day from the beginning of menstruation, ovulation falls, which is the moment of conception (its date). As you can see, creating a calendar of childbirth and calculating the day of future childbirth by the date of conception is completely easy on your own. If you want to know exactly the PDD by menstruation, you need to decide on the specific moment of the release of a mature egg. There are 4 ways to do this:

• Ovulation test. The pharmacy sells tests to accurately determine the release of the cell. According to the instructions, the strip must be dipped in urine for a few seconds and studied how the color of the reagent has changed, which shows the concentration of the peptide (luteinizing) hormone responsible for follicle rupture
• Microscope. We are talking about a reusable device with which you can see the patterns of the salts contained in saliva. By the time the cell appears, the pattern becomes like a fern.
• Vaginal discharge. When the follicle develops, vaginal mucus does not come out, as it has a fairly thick structure. At the moment of the "birth" of the egg, it liquefies and is excreted in large quantities (color - egg white). Such discharge can be until the moment when the cell dies.
• Painful sensations. In the area of ​​the ovary, unpleasant sensations are possible, because a torn follicle is an ordinary wound that can cause pain. A woman who knows her body perfectly and follows the sensations will never miss the day of the onset of pain. And already relying on this knowledge, you can calculate the date of birth by conception.

As you can see, the second method is closely related to the first. To some extent, they complement each other.

Determination of the duration of pregnancy by a doctor based on the results of a gynecological examination

At your doctor's appointment, be prepared to hear questions related to your last period, duration, characteristics, etc. A gynecologist who has confirmed the presence of pregnancy is obliged to inquire exactly what dates the last menstruation took place, when they began, how long they lasted.

In some cases, gynecologists determine the date of conception by the delay in menstruation. Therefore, every self-respecting girl, woman must necessarily keep a calendar of cycles, not forgetting to indicate the beginning and end of women's days in it. An attentive attitude to yourself and your health can help in establishing a more accurate DA. For some reason, some expectant mothers are convinced that only a gynecologist who observes the expectant mother can determine for sure the exact date of delivery. But in reality, the specialist unlocks in his calculations the same data that were named in the previous methods for calculating the PDR. Even if you decide to change your doctor, the new gynecologist will ask you:

• when did your period start;
• what was the duration of the menstrual cycle;
• how systematic were the periods, were there any failures and any deviations in them.

These criteria are the basis for the study of the expected day of birth. In many cases, this day coincides with the PDD calculated by the date of conception online. Sometimes there is an insignificant error of one or two days, the cause of which is unaccounted for points, the "human" factor. After the gynecological examination, the doctor can call the PDR. An experienced gynecologist determines pregnancy by touch. He studies the shape of the uterus and its size (in all girls it has a pear-shaped shape, and in expectant mothers the uterus is enlarged, presented in the form of a ball). These indicators are quite enough to determine the DA. A knowledgeable specialist who works every day with pregnant women can quickly calculate day X in his mind. As practice shows, from the third or fourth week, you can correctly name the length of time the pregnant woman is. If you have a pregnancy for more than 3 months, it is almost impossible to find out the reliable period, because all children develop according to an individual scenario.

Determining the duration of pregnancy using ultrasound

Calculations of the calculator are often inferior to the calculations of the date of the upcoming delivery by ultrasound. An ultrasound examination allows you to find out the size of the embryo, and the doctor, comparing the results with the standards, talks about how the pregnancy is progressing. Could there be mistakes here? Undoubtedly. As noted earlier, all organisms develop in different ways, and therefore, at the same time, different girls may have embryos of different sizes. And yet, the determination of PDD by ultrasound is considered the most reliable method.

Girls who have undergone an ultrasound examination before 12 weeks will find out the date of conception and delivery with a high probability (up to one or two days). Using ultrasound, doctors determine the duration of pregnancy in the 2nd or 3rd trimester, but the findings are not taken as a basis. The difficulty of determining the date of the onset of labor activity is due to the fact that it is necessary to take into account the individual characteristics of the development of the fetus, the complexion of the expectant mother and many other factors. Therefore, if you want to know for sure on what day fertilization took place, when exactly you will give birth to your little happiness, come to the consultation with the gynecologist early. He will tell you how long the pregnant woman is, and will help determine the date of conception. It is possible that this will help you get answers to your questions.

Which of the above is the most effective method?

The most accurate method by which the calculation of the PDD is possible is ultrasound. This method is the most reliable, as it shows high accuracy. The next most popular, accuracy can be called the method of counting the day X from the day of the last menstruation. If the results of this method match the results of an ultrasound scan, the chances of having a baby on the expected day are significantly increased.

What to do if the dates for the ultrasound scan and for the last monthly ones did not coincide? In the first place, you shouldn't be upset. The main thing is to monitor your health, visit your gynecologist regularly and go through all the examinations that he prescribes. Whichever option you choose to calculate the long-awaited delivery date, the result will not be 100% accurate. It is almost impossible to determine the exact day of the birth of a baby. A few mummies, independently or with the help of a doctor, set the correct date of birth.

It is important! Women carry under the heart of their children not nine calendar months, as many believe, but 40 weeks or 280 days, ten lunar months. Therefore, you should not add nine months to the date of conception. Some women give birth at 38 weeks, some a little earlier. And this is the norm. Expectant mothers of twins, triplets give birth earlier than the designated date. That is, in this case, it is important to understand that whatever date you calculate, or whatever date the gynecologist calls, you can give birth to a baby 1-2 weeks earlier or later. This is not considered a deviation.

The duration of carrying a child depends on many factors: the state of health and age of the mother, stressful situations, diseases, all kinds of complications, polyhydramnios, the presence of high blood pressure or diabetes in a pregnant woman, the number of previous pregnancies, etc. Recently, unpredictable miscarriage of pregnancy or its prolongation is especially common. That is, even theoretically, it is impossible to know the reliable date when the child will be born. This is confirmed by statistics: about 17% of women give birth on the appointed day, the other 83% give birth a little later or a little earlier.

No experienced specialist can predict the exact onset of labor. Thus, it is simply impossible to find out, calculate the day of the upcoming birth with a 100% probability. But you can find out the DA. And the methods listed above will help you. With their help, you will surely determine when conception was (approximate date of fertilization), when the baby will appear. If you wish, you can use the virtual calculator for calculating the PDR at any moment.

It will take you no more than two to three minutes to quickly calculate the due date by the date of conception using such a service. Many mothers, long before visiting the doctor's office, first want to calculate the date of conception, and only then, having indicated the date of conception in the service, they will find out the PDD. But it is better, of course, to do an ultrasound. Tips and tricks for those who consider the DA on their own:

1. It makes no sense to get hung up on calculating the date of birth, the probability of a 100% hit is small.
2. The expectant mother needs to prepare mentally in advance for the fact that childbirth may not come on time.
3. If your female cycle is standard (28-30 days), then the date of birth that the gynecologist calculated for you will be close to the truth.
4. Women who experience disruptions in the menstrual cycle should inform their gynecologist about this. Labor may start later or earlier (the difference will be as many days as how many days your cycle is longer or shorter than the standard twenty-eight days).
5. If for the first time you gave birth right on time, this does not mean that everything will be the same with the second birth.
6. It is important to remember and understand: information on PDD is needed primarily by medical workers to establish possible abnormalities in the development of the fetus, assess the maturity of the placenta, observe important indicators in order to promptly hospitalize the mother or stimulate delivery.

If your pregnancy is not planned, the first thing you should do is not to panic. It will be difficult for you to make really accurate calculations. Use any of the proposed methods and determine the date of conception. Having an idea of ​​the duration of waiting for a baby to appear, it is easier to calmly prepare for childbirth. Namely, calmness is the key to successful bearing of the fetus. Live in faith: when your baby is fully prepared for life outside of mom's tummy, then he will decide to be born. So, as soon as your pregnancy test shows two stripes, rejoice: you will soon be a mommy. This is real happiness for any woman, save it.

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 morally tune in to the process of childbirth. If there are several ways on how to calculate the due date on your own.

The estimated due date (PDD) is the number when labor should begin after forty weeks of carrying a baby. This is a rough estimate as thirty-seven weeks is the period from which a pregnancy is considered full-term. A 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 pass for so long and stimulate labor artificially.

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

The time of the baby's birth 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 the day of birth. 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 which particular day of intimacy conception occurred. The calculation of the approximate number of births of a 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 received date or subtract the same amount. This error is due to the fact that the man's seed can be viable in a woman's body for a week.

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

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

The error is also 3-5 days.

By the last menstrual period

When calculating the date of birth according to the last menstruation, two methods are used.

1. 280 days are added to the first day of menstruation. The resulting date will be the estimated due date. The essence of this calculation is that the difference between the beginning of the cycle and the day of ovulation is two weeks.
2. According to Negel'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 estimated time of the baby's birth, it is recommended to subtract 3 months from the first day of menstruation, and a week is added to the result obtained. On this day, exactly one year later, childbirth should take place, taking into account an error of several days.

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

Medical professionals usually use the second method when calculating the due date.

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 timing of pregnancy before the day. To do this, it is recommended to conduct it in the first trimester. Knowing the period, the date of ovulation or menstruation is determined. This allows you to calculate the estimated date of birth of the baby in several ways.

The ultrasound itself can also provide information about the day of labor. For 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, then the specialist may get lost in the count. In this case, he states that the period for carrying the baby was incorrectly determined and moves the date of the onset of labor.

According to the first movements

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

According to statistics, the baby begins to move after the 20th week of conception, if the pregnancy is the first. If the mother carries the baby for the second and subsequent times, then the baby will make itself felt after the 18th week. As practice shows, a woman can feel the first movements before the due date for 14 days. This also happens two weeks later than the due date. 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 the mother has a second birth and subsequent ones, then 22 weeks are added to the date. The resulting figure will be the estimated date of the onset of labor.

Based on the results of a gynecological examination

An experienced doctor, based on the results of the examination, can determine how many a woman should give birth. The specialist builds 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 delivery, the doctor bases on the duration of the pregnancy at 40 weeks. This is the average rate for carrying a baby.

In the early stages of conception, a gynecological examination does not provide data on 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 helps determine the obstetric examination. Such data are also approximate, since the result depends on the internal feelings of the doctor and his work experience.

As clinical studies show, when pregnancy reaches four weeks, the uterus becomes the size of a hen's egg. At the eighth week of gestation, the dimensions increase to the size of a goose egg. In 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 the baby's birth only in the first trimester. If the expectant mother applied at a later date, she is advised to use other methods to correctly determine the due date.

Which method is considered the most effective

The most effective method for determining the date of onset of labor is ultrasound.

It shows the state of the placenta, how the baby's head is located relative to the entrance to the small pelvis, the level of development of the child and the size of the opening of the cervix. Comparing all these factors, the specialist as accurately as possible names the period of bearing the baby, and already, based on this, the date of birth is calculated.

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

Gynecologists often determine the date of expected birth by menstruation. They use the Negel formula for this. To use this method of counting, the doctor should ask the expectant mother whether she regularly has her periods or not.

If the answer is negative, the specialist is obliged to use other methods of calculating the number of onset of labor, otherwise an inaccuracy may be made, which will lead to the onset of childbirth outside the hospital or a woman's stay in the hospital for too long.

The rest of the methods can be used as additional methods for the most accurate calculation of the day of birth.

Why DA results are considered approximate

According to statistics, only 5% of women in childbirth have babies on the date that they calculated or the specialist told them. No method has been developed to determine the exact day of birth. Each of the methods has an error of 3-5 days and even two weeks.

Ultrasound scans can also be inaccurate if the baby is in an awkward position in the uterus. Deviations in timing are also provoked 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 date of the baby's birth:

• the age of the expectant mother;
• pathologies that a woman underwent during the period of bearing a baby or diseases in a chronic form that arose before pregnancy;
• location of the placenta;
• ecological situation in the region of residence;
• the state of the nervous system;
• harmful addictions;
• the size of the child and multiple pregnancies;
• the level of development of the child;
• repeated pregnancy;
• heredity.

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

Conclusion

How to calculate the due date as accurately as possible? Unfortunately, even a specialist can only name an approximate date for the birth of a baby. But even such data is usually enough to morally tune in to childbirth and prepare everything that is 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 approximate, it is not recommended to rely on it with 100% certainty.

The portal for mothers, the site knows that mothers are worried about any reason and it is important for them to know everything that happens to her body before, during and after pregnancy. Not to mention the estimated due date! Especially for visitors to the Mamapedia website, a free online service has been created to determine the date of birth by the date of conception of the child. All that is required of you is to indicate the date of conception of the child, and the pregnancy calculator will specify your date of birth. In addition to the exact date of birth, the service will also indicate important information about important points during pregnancy and examinations.

If you are not sure of the exact date of your last menstrual period or the date of conception, the pregnancy calculator will give you the approximate date of due date. With a planned ultrasound examination - you can find out the exact date of your birth!

Calculation of the due date will take a matter of seconds, and will not make you wait long. You can calculate the due date absolutely free of charge and without registration.