When a baby is born a calculator by the date of menstruation. How to calculate the date of birth: methods. Why DA results are considered approximate

How to find out the date of delivery? About the methodology for calculating the date of birth

For calculating the estimated date of delivery obstetrician-gynecologists have a very convenient and uncomplicated formula: 9 months and 7 days are added to the date of the first day of the last menstruation. And you can calculate even easier - from the first day of the last menstruation, they count back 3 months and add 7 to the resulting number.

Estimated date of birth \u003d date of the first day of the last menstruation + 9 months + 7 days.

Estimated date of birth \u003d date of the first day of the last menstruation - 3 months + 7 days.

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

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

Calculation of the date of birth on the day of conception is not an accurate method for determining the term of labor. Even if you know for sure the day when sexual intercourse occurred, this does not mean that it was on this day that conception occurred, since sperm cells are able to remain active in the vagina for up to several days.

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

Determination of gestational age using ultrasound

In the early stages, up to 12 weeks of pregnancy, it is possible to calculate the date of birth with the help of ultrasound quite accurately. For longer periods, this is often difficult due to the fact that each child grows at his own pace. Namely, such indicators as the sizes of different parts of the body of the fetus are the basis for calculating the gestational age.

Determination of gestational age during a gynecological examination

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

Determining the gestational age for the first stir of the child

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

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

Every pregnant woman looks forward to the birth of her baby. And, as a rule, the question of when the day of birth comes, begins to worry the future mother at the very beginning of pregnancy. There are many different methods that are used to determine the approximate date of birth. But how to calculate the date of birth as accurately as possible? Let's try to do it together!

Determining the estimated date of birth on the day of conception is quite easy. As everyone knows, the best time for pregnancy is considered the day of ovulation, which occurs approximately in the middle of the cycle.

If a woman knows the day when ovulation occurred, then calculating the date of birth will not be difficult. Some women experience malaise and strong sex drive at the time of ovulation, but there are special rapid tests to accurately determine this day.

You can determine the day of ovulation by ultrasound. If you do not know when you ovulated, then you can calculate this day approximately, it is enough to calculate the middle of the cycle.

The date of birth is calculated by adding 280 days to the day of ovulation (this is how much the pregnancy lasts). A more accurate date can be calculated by knowing when sexual intercourse occurred. Remember that sperm can fertilize the egg within a few days, which is why the date of conception and the date of sexual intercourse may not coincide.

We determine the date of birth by the last monthly

Coming to the gynecologist for an examination, the first question a woman hears sounds something like this: "When did you have your last menstruation?"

Women who do not follow the regularity of their periods may find it difficult to answer this question. To determine the gestational age and calculate the estimated date of birth, the doctor needs to know the first day of the last menstruation.

Gynecologists use a simple and well-known formula to determine the date of birth by the last month: for this it is enough to take three months from the first day of the last menstruation and add 7 days.

Of course, one cannot talk about the unquestionable accuracy of this calculation method, it is more suitable for women with a constant cycle of 28 days. If the woman’s cycle was irregular, then this method should not be used for calculation.

Determining the date of birth by ultrasound

Ultrasound examination is an effective diagnostic method, this study is safe for both mother and future baby and allows with high probability, based on the size of the fetus, to determine the estimated date of birth.

The most accurate determination of the expected date of birth by ultrasound can be in the first trimester, later the size of the fetus may slightly differ from the established ones.

Determination of the approximate date of birth during examination by a gynecologist

An obstetrician-gynecologist, examining a pregnant woman, determines the degree of increase in the uterus. This helps to predict the approximate date of birth quite accurately. The uterus grows with the baby, therefore, as a rule, it is not difficult for an experienced specialist to calculate the PDR (estimated date of birth).

According to the size of the uterus in the first trimester of pregnancy, the doctor can calculate the gestational age, and then calculate the estimated date of birth, based on the approximate date of the last menstruation.

In the second and third trimester of pregnancy, determining the approximate date of birth during examination by a gynecologist may be difficult because the uterus increases in size in each pregnant woman with different intensities. That is why in later pregnancy, this method is considered ineffective.

We calculate the date of birth on the first stir of the baby

In those days when there was no ultrasound examination, the most accurate method for determining the approximate date of birth was considered to be the method of determining the date of birth by the first stir of the child.

Of course, and at present, the doctor finds out the date of the first stirring from the pregnant woman, enters it into the woman’s exchange card, but they don’t attach much importance to this date.

If you rely on this method for calculating PDR, it is worth noting that it is believed that primiparous women feel the baby move during pregnancy at 20 weeks, respectively, another 20 weeks must be added to the date of first stirring to get PDR.

Women with a second and subsequent pregnancies may feel the baby move a little earlier - by 18 weeks, that is, in this case, to calculate the DA, it is worth adding 22 weeks to this date.

This method for calculating PDR can also not be considered absolutely accurate, since due to physiological characteristics, some women can feel the baby moving at an earlier date, in addition, some pregnant women who lead an active lifestyle can easily not catch the moment of the first stir.

Future mothers who are forced to observe bed rest due to the threat of abortion are very sensitive to all the changes in their body, such pregnant women can also feel the movement much earlier than is commonly believed.

Calculation of DA based on obstetric examination

After the 20th week of pregnancy, at each examination of a pregnant gynecologist measures the height of the uterine fundus and the volume of the abdomen. These measurements help the doctor to monitor the course of pregnancy and in time to determine the presence of any deviations from the norm, because for each period the measurement numbers are certain. These data can help your doctor calculate the estimated date of delivery.

One cannot completely rely on this method for determining PDR, because the inaccuracy of the doctor or the individual characteristics of the body of the future mother can affect the testimony during measurement.

For example, in women with oligohydramnios, the abdomen is smaller and the height of the uterine fundus is also smaller than in a woman whose pregnancy is normal. Accordingly, the indicators during measurement will change, which will lead to incorrect formulation of the DA.

Why is the exact date of birth determined, but only an approximation?

It is believed that pregnancy should last 40 weeks or 280 days, however, often enough, labor begins at 38 weeks and this is also considered normal. If the pregnancy is multiple, then, as a rule, childbirth always begins earlier than the period established by the gynecologist.

It should be borne in mind that a child can be born not only earlier than the specified period, but a couple of weeks later than it was established by a gynecologist - this is also not considered a deviation from the norm.

At 38 weeks, the fetus is already fully formed, the pregnancy is full-term, therefore, which began a couple of weeks earlier than the birth, should not scare and cause panic in a woman.

If the baby is born within two weeks after the expected date of birth, then pregnancy is also not considered to be postponed.

Do not forget that various factors can influence the course of pregnancy and the estimated date of birth. Various diseases, complications during pregnancy can lead to premature birth.

In fact, the preliminary date of birth is most important for the future mother, because it is she who is waiting for the baby to appear.

However, the baby will be born when it is finally ripe and completely ready for life outside the womb, it is then that certain changes occur in the pregnant woman’s body, indicating the onset of the birth process. It is quite difficult and difficult to calculate when this long-awaited moment will come, that's why the date of birth is called the estimated or approximate.

How to calculate the preliminary date of delivery using the online calculator?

Your pregnancy guide can be a pregnancy calendar that tells you about the signs of pregnancy, the development of the baby and the state of the pregnant woman in a particular week of pregnancy, as well as a pregnancy calendar that helps you determine the date of the upcoming birth and tells you what tests and examinations you need to go through and what week of pregnancy it costs to do.

Pregnancy calendar helps a woman track changes in her body at different stages of pregnancy, as well as determine the estimated date of birth, using a special online calculator.

In order to determine the estimated date of birth online, using a calculator, you need to know the first day of your last menstruation. The calculation is carried out in approximately the same way as already described above using the Negele formula.

What methods of calculating DA are worth believing?

Of course, it is best to use the results of an ultrasound examination and the calculation of the PDD by the date of the last menstruation to determine the approximate date of birth - these methods are considered the most accurate. If these data coincide, then this is fine, but even if they differ, do not be upset, you should carefully monitor how the pregnancy proceeds in order to exclude various pathologies and calculate the estimated date more accurately.

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Determining the gestational age and estimated date of birth is very important for a woman and her doctor. Many laboratory and instrumental studies are prescribed exactly at the time when it is easiest to identify the pathology in time. Comparison of fetal parameters with the average indicators of each period of pregnancy helps to identify and correct underdevelopment. Clarity in determining the date of birth of the child allows you to carefully prepare for this event and in time to open the sick leave, so that the woman has time to gain strength before childbirth.

There are several methods to help you calculate the required metrics. An obstetrician-gynecologist uses them in combination, since almost every method has an allowable error associated with subjective reasons: the individual characteristics of a woman, elementary forgetfulness - it is difficult to remember the date of the last menstruation. The term of the expected birth can be determined quite approximately, since a full-term pregnancy lasts from 38 to 42 weeks, and this is normal from the point of view of physiology.

Negele Formula

The method of calculating the term of labor according to this formula is excellent for women with a constant standard cycle lasting 28 days. The Negele formula is simple - to determine the desired date you need to subtract 3 months from the first day of the last menstruation, and then add 7 days to the resulting figure. If the menstrual cycle was constant, but lasted longer or shorter than the standard, the difference between your own and the standard cycle should be added to the received date or subtract the same number of days.

How to calculate the term of labor by the date of ovulation?

If a woman in the month preceding conception determined the onset of ovulation at basal temperature, this will help to accurately determine the gestational age. Conception occurs on the day of ovulation, when the egg ready for fertilization leaves the ovary. If sexual intercourse took place 1-2 days before ovulation, the spermatozoa remain ready for fertilization all this time, that is, conception can occur a short time after sexual contact. If you add 38 weeks, or 266 days to the date of ovulation, you can find out the estimated date of birth of the child.

If a woman does not know when ovulation occurred, but has a stable 28-day menstrual cycle, it is assumed that conception occurred in the middle of the cycle, that is, on day 14. With an irregular cycle, this method has an error.

Determine the date by moving the child

The date when a woman first felt the baby’s stirring is very important for correcting a comprehensive calculation of the term of the expected birth. Although the fetus begins to move from the twelfth week, for the first time, most women feel these gentle movements in the middle of the gestational period, that is, in the twentieth week. However, this rule does not apply to everyone - during the second and subsequent pregnancies, a woman can feel the first movements 2 weeks earlier.

A nulliparous woman of fragile physique also has such an opportunity, while a pregnant woman, who has a solid complexion, feels movements later. These sensations can be called subjective, because they depend on the sensitivity of the woman to what is happening in her body. The thickness of the myometrium also affects the severity of the child's movements.

All these nuances mean that the above method of determining the date of birth can not be considered the main one, it is used only in combination with other methods.

What do obstetrician-gynecologists consider the gestational age?

When calculating the gestational age, the doctor usually relies on the start date of the last menstruation, however, the basic calculations are carried out taking into account a set of different criteria.

Uterine size

In the early stages of pregnancy, when individual differences in fetal size are not yet apparent, you can determine the date of birth using this technique. At a period of 4 weeks, the size of the uterus is compared with a chicken egg, at a period of 8 weeks - with a goose.

From the twelfth week, this method is already difficult to apply, since in the future, the parameters of the uterus and fetus differ in different women with the same period.

By ultrasound

The method for determining the term of labor according to the ultrasound scan data is valid at the beginning of the gestational period, more precisely, until the third month. After twelve weeks, it is impossible to accurately determine the date of birth, based on ultrasound data, due to the individual differences in the fetal parameters in women of different constitution.

Uterine fundus height

This method has been used by an obstetrician-gynecologist since the beginning of the second trimester. The longer the fetus develops, the higher becomes the bottom of the organ, which rises beyond the small pelvis.

The height of the bottom of the uterus is determined when a woman lies on her back. The doctor carefully palpates the abdomen and measures the distance from the pubic joint to the bottom of the uterus. This indicator increases evenly throughout the gestational period, and immediately before birth, the uterus lowers.

When using this technique, an error of 2-3 cm is laid. It can be caused by polyhydramnios, pregnancy with twins or triples, the age of the woman, the size of the fetus. To clarify the indicators, the pregnant woman’s waist circumference and fetal parameters are taken into account.

Calculation of the height of the uterine fundus by weeks:

8-9 weeks - height 8-9 cm, the uterus is still located within the pelvis;

10-13 weeks - height 10-11 cm, the uterus increases, the placenta develops intensively, the cardiovascular system of the fetus begins to work;

Week 16-17 - height 14-18 cm, the uterus is between the navel and the pubic joint, the fetus looks like a little man, all of whose organs are already laid;

Week 18-19 - height 18-19 cm, the unborn child develops arms and legs with fingers, cerebellum, immune system, the placenta fully assumes responsibility for ensuring the functioning of the fetus;

20 weeks - the height of the uterus in centimeters corresponds to the gestational age in weeks;

21 weeks - a height of 21 cm, from now on, the standing height of the uterus will increase by 1 cm weekly, now it is 2 fingers below the navel.

22-24 weeks - height 22-24 cm, the bottom of the uterus at the navel, is easily determined by palpation, the body weight of the fetus is 0.6-0.7 kg;

Week 25-27 - height 25-28 cm;

28-30 weeks - height 28-31 cm;

32 week - height 32 cm, the upper edge of the uterus is located between the xiphoid process of the sternum and the navel;

Week 36 - height 36-37 cm, the uterus is felt on the line connecting the costal arches;

39 weeks - height 36-38 cm, the uterus begins to lower, the weight of the fetus exceeds 2 kg;

40 weeks - the height of the uterus is reduced to 32 cm, it is again between the navel and ribs, the child is ready for delivery.

By head size and fetal length

The following methods are used to calculate the gestational age:

Method Jordan. The term is calculated by the formula X \u003d L + C, where X is the term in weeks, L is the length of the fetus (cm), C is the diameter of its head (cm).

Skulsky's method. Here the formula is: X \u003d (L x 2) - 5/5, where L is the length of the fetal body (cm), the number 5 in the numerator of the fraction is the thickness of the myometrium, and the number 5 in its denominator is a special coefficient.

Any calculations are only a rough guide. According to medical statistics, only 10-17% of babies are born on time, the rest are born earlier or later than expected. Many factors influence this circumstance: heredity, pregnancy pathologies, stressful situations, and other causes.

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The gestational circle is a convenient and simple tool for determining the gestational age, estimated date of birth, as well as some other information about pregnancy. Our gestational disc allows you to determine not only the gestational age, date of birth, but also the height and weight of the fetus, and even the zodiac sign of the future the child.

Using our gestational circle is very simple.

If you do not know the duration of your pregnancy, scroll the inner circle so that the green arrow points to the first day of your last menstruation.

green arrow

Wherein arrow today will indicate the current date and week of pregnancy, as well as the height and weight of the fetus. Then arrow pdr will indicate the estimated date of delivery.

today arrow

If you already know your term, then scroll the inner circle so that arrow today indicated the week of your pregnancy. Then she will indicate the height and weight of the fetus, and arrow pdr will indicate the estimated date of delivery. In this case, the green arrow will indicate the first day of the last menstruation.

arrow pdr

What does “gestational” mean?

Many first hear this word in antenatal clinics. Latin gestatio literally translates as "gestation." Therefore, "gestational" means "related to pregnancy."

The gestational age is calculated from the moment of conception. Determining exactly when this happened is extremely difficult. Implantation of a fertilized egg may take up to several days after intercourse. At the initial stage of embryo development, even a few hours play an important role. Therefore, the inaccuracy in the definition of the "starting point" leads to the relative conventionality of the calculation.

Gestational disk for determining the date of birth

There are different calculators, the main purpose of which is to establish the date of the baby's appearance. Gestational circle - An indispensable tool for preparing for childbirth and better control over the pregnancy process. With it, every woman can at home determine the "date of X." This is necessary, since preterm and belated births pose the same danger. Therefore, it is important to calculate the estimated day of birth and, as it approaches, carefully monitor the body's signals.

Statistics say that about 2% of babies are born on exactly the calculated day. The date that the calculator will show is better considered conditional. Most likely, the child will be born a few days earlier or later. Normal births are considered between 38 and 40 weeks. But each organism has its own unique features. Some women wait up to 42 weeks, in which case maximum attention from doctors is required.

The gestational circle is one of the most informative calculators. In addition to the estimated date of birth, it can be used to determine the height and weight of the embryo as it develops. In addition, many parents are wondering under what zodiac sign and in which year of the animal according to the Eastern calendar a child will be born. This helps some couples choose a name.

How is the gestational circle

Using this visual calculator, you can easily determine the date of birth and during pregnancy to track the height and weight of the fetus. The external drive is divided into 12 months. Each day corresponds to one division on the scale. For convenience, long marks are indicated every 5 days.

The numbers 1-40 on the moving part of the disk correspond to the weeks of pregnancy. Trimesters are also highlighted using a background with different saturations: the first - from to, the second - from to, the third - from to. Closer to the center is the weight scale, and at the last level is the growth of the fetus.

There are 3 arrows on the circle: thin green (the first day of the last menstruation), PDD (estimated date of birth) and a static “today”. The main information is displayed in the center of the circle: the beginning of the last menstruation, the estimated date of birth and the baby’s zodiac sign. In the area under the disk, the number of weeks and days before childbirth is instantly calculated, as well as the zodiac characteristics.

How to determine gestational age using a gestational disk

Many obstetrician-gynecologists in various countries, including Russia, use the gestational circle. The simplicity of the method allows it to be applied to absolutely every woman.

When planning a pregnancy, it is especially important to maintain a menstrual calendar. This will help to determine the estimated date of birth as accurately as possible. To calculate the gestational age for gestation, just move the thin green arrow to the date the last menstruation begins. The arrow of the DA will indicate the date of birth, provided that the pregnancy ends at 40 weeks. The arrow "today" is easy to track the average height and weight of the fetus in each week.

For example, the last menstruation was from December 12 to 16. For the calculation of the gestational circle, only the first date is important - December 12th. Set the thin green arrow to this number. As you turn the arrow, pay attention to the center of the circle. This is much more convenient than peering into divisions. The arrow “today” indicates that the woman is at the beginning of the 8th week of pregnancy, the fetus has grown to 18 mm and weighs 1 g. Prepare for childbirth within 1-2 weeks of September 18th.

What to do to a woman who does not know the date of the last menstruation?

To independently determine the date of birth of the child in this case, the gestational circle will be ineffective. Usually, doctors prescribe a blood test for hCG. Chorionic gonadotropin is a hormone that is secreted in a woman’s body after implantation of a fetus in the uterus at 4 obstetric weeks. From this moment you can get the most reliable results.

When using the strip test at home, the second strip may be translucent. This indicates either the unsuitability of the test, or a small amount of hCG hormone in the body. To obtain reliable results, you need to try again in a week if menstruation does not begin. A weakly expressed second strip can appear in women taking hormonal drugs, regardless of pregnancy.

A home test shows only the presence of pregnancy. The result of a biochemical blood test determines its duration. Do not postpone checking. HCG analysis is most reliable in the first 12 weeks. Gradually, the level of the hormone decreases, and at a later date it is difficult to determine the time of conception.

When the week of pregnancy becomes known, you can use the gestational circle to calculate the date of birth and determine the size of the fetus. To do this, just set the arrow "today" to the mark corresponding to the current term.

For example, there is 9 weeks. At this stage of development, the embryo has reached 23 mm and weighs 2 g. The estimated date of birth is September 9th. The green arrow indicates the approximate start date of the last menstruation.

Inaccuracies

Bearing a fetus is a complex process, which every woman proceeds in a special way. Moreover, the course of the first pregnancy does not mean at all that in the same scenario I will go through the next ones.

Pregnancy calculator makes a certain error. In addition, when setting the initial data, errors are not excluded. The accuracy of the calculation depends on the individual characteristics of the body. The wheel of pregnancy shows the most accurate result with a standard menstrual cycle of 28 days. If the duration is longer, for example, 35 days, then ovulation will occur on average on the 21st day. This leads to an increase in the difference between obstetric and fetal periods.

In addition, the error can be triggered by an inaccuracy in determining the embryonic period. The sperm can persist in the female body for up to 3 days. Fertilization can occur at any time. Taking into account all factors, including the individual characteristics of the body of the expectant mother, the error in calculating the estimated date of birth often reaches 2 weeks. Ultrasound gives more accurate results, although the calculation method at the beginning of the last menstruation is recognized as one of the best worldwide.

Why in the first two weeks the height and weight on the disk correspond to zero

You may notice that in the first two weeks the indicators are zero. However, this period is part of the entire pregnancy cycle. The fetus in the womb develops surprisingly quickly. Therefore, in determining the date of birth is important every day. However, there are different terms - obstetric and embryonic, which are important not to be confused.

Some mistakenly believe that the first week is counted from the moment of conception. In fact, pregnancy begins on the last day of the menstrual cycle. Immediately during this period, the birth of a new life might not have occurred. The moment of conception depends on ovulation and varies within a couple of weeks.

With a standard menstrual cycle lasting 28 days, the process of ovulation occurs on day 14. In this case, the embryonic period will lag behind the obstetric period by about 2 weeks. In practice, this means that at the end of the first month of pregnancy, the actual age of the embryo is only 2 weeks.

Why sometimes calculations do not match with different methods

Many women are surprised to find that the dates of birth do not coincide according to various estimates. Which one to believe?

In official medicine, it is believed that during the first trimester, embryos develop equally. On ultrasound, the gestational age is determined by the table of the correspondence of the size of the fetus to a certain development period. For example, the calculation according to the last menstruation shows the result of 12 weeks, and the diagnostician calls 11 weeks. The term established during the first ultrasound is considered to be more reliable. In the above example, the difference is due to early ovulation, but it can be late. For a doctor, the result of an ultrasound scan is a priority.

During the second and third trimesters, each fetus develops at its own pace. Therefore, data from averaged tables may not fully correspond to reality. Deviations within one week are considered normal. In the ultrasound protocol, the specialist indicates to what period the development of the fetus corresponds.

The gestational circle gives an idea of \u200b\u200bhow the unborn baby develops every day. At the beginning of the first trimester, the embryo gains only a couple of grams every week, but the difference, for example, between 21 and 21 weeks is an average of 71 g. Each woman is interested to know how the fetus changes. With the gestational circle, observation becomes simple and even more fun.

The most important weeks of pregnancy

In order for the fetus to develop correctly and the baby to be born healthy, the fact of pregnancy must be established as early as possible. It is not at all necessary that the expectant mother will intuitively sense the conception, or from the first weeks there will be obvious signs in the form of aggravated sense of smell, morning sickness, etc. There are often cases when a woman learns about pregnancy only by an enlarged stomach.

For pregnant women, the following factors are of particular danger:

Unhealthy habits.
Stress.
Unbalanced diet, deficiency of nutrients (mainly iron and folic acid).
Great physical activity.
Overheating or hypothermia.
Taking medications incompatible with pregnancy.
Infectious and inflammatory diseases.

It is necessary to prepare the body for pregnancy in advance in order to minimize the risks for the fetus and the expectant mother. But even if everything is going according to plan, special care must be taken in certain periods. If at any stage of pregnancy a woman feels severe discomfort, burning or even unreasonable anxiety, you should visit a doctor.

When to be particularly careful

The critical periods coincide with the phases of the active increase in the embryo and placenta. The most dangerous weeks are as follows:

I trimester - 2-3, 4-7, 8-12.
II trimester - 18-22.
III trimester - 28-32.

The insidiousness of the first weeks lies in the fact that a woman may not be aware of pregnancy. As a result, prerequisites are not met. From 4 weeks, the main organs are formed. During this period, it is especially important to comply with the doctor's prescriptions in order to prevent pathologies. At the last critical stage of the first trimester, a placenta is formed - a natural shield that will increase with the fetus.

The period from 22 weeks is considered the most important. At this time, the future baby is most active. The biggest risks to a woman’s fetal life and health are sexually transmitted infections. One of the main conditions is to use barrier protection during sexual intercourse.

By the beginning of the third trimester, the fetus is as similar as possible to a baby, however, it is not yet able to survive separately from the mother's body. The causes of preterm birth may lie in placental abruption, infections and ischemic-cervical insufficiency. To prevent this, you must follow absolutely all the doctor’s instructions, protect your own health and eliminate stress.

There were no critical periods on the gestation circle. This is because they do not have to be difficult at all. The more you concentrate on the dangers, the stronger the destructive effects of stress. You can use the wheel of pregnancy during the entire period of gestation. On the diagram it is convenient to track the transition to a new trimester, the stages passed and the approximation of the date of birth.

Description

A universal pregnancy calculator is a convenient and practical tool for calculating a number of parameters that are important and interesting for a future mother. The calculator is a circle that looks like a watch dial, the inside of which can be rotated by setting this or that hand in the desired position. For example, by setting the thin green arrow so that it indicates the first day of your last menstruation, you can determine the date of future birth using the "PDR" arrow, and the "today" arrow to find out what your week of pregnancy is, and what height and weight of the fetus present day. The Wheel of Pregnancy can be used in another way. For example, if the birth has already taken place, then you can set the arrow "PDR" (estimated date of birth) so that it indicates the date of birth. Then a thin green arrow will show you the date on which you had your last menstruation before pregnancy. Among other things, the calculator determines the zodiac sign of the unborn child, and even his zodiac animal according to the eastern calendar.

This day needs special preparation. So much you need to buy, cook, study a huge amount of literature, think through all the possible options for the development of events. And it seems to us women that it’s a shame not to take something into account.

The whole pregnancy is not only a spiritual attitude, but also quite material chores that should be carefully planned.

In a simple formula birth date calculations the main component is the gestational age. Conception occurs most often in the days of ovulation, but not every woman knows when these very days come.

Everything is simple - exactly in the middle of the menstrual cycle, i.e. after 12-16 days from the first day of the last menstruation.

For example, your last menstruation began on April 1, which means that the egg will go on its difficult path on April 12-16.

This calculation of the term of birth is suitable for women with a menstrual cycle of average duration - 24-28 days. With deviations every day in one direction or another, the period of ovulation also changes.

We assume that the conception occurred in the middle of the last menstrual cycle. From this period of time, the long 40 weeks of your pregnancy begin.

We are trying to calculate the term of delivery by week.

Some women mistakenly add 9 months and get the "estimated" secret date. This is incorrect because pregnancy lasts a little longer - approximately 280 days or 40 weeks.

True, the doctor quickly eliminates this error and helps the patient determine with the help of a special calendar that any gynecologist has.

This calendar has the easiest counting system - from the first day of the last menstruation you need to subtract 3 months (April 1 minus 3 months \u003d January 1), then you need to add 7 days to the resulting date (1 + 7 \u003d 8), the result obtained is the expected term childbirth, which your gynecologist will put on the card.

The second method of calculation - 280 days should be added to the first day of the menstrual cycle.

But you can not rely solely on these calculation systems, because for some, full-term pregnancy can last 38 weeks, while for others - 42, all this is within the normal range.

A multiple pregnancy usually ends earlier than the date calculated by the doctor.

How to correctly calculate the term of labor by stirring. Omens

To determine the term of childbirth, you can use a popular sign, which for many centuries, even before the development of medicine, has helped future mothers.

Exactly in the middle of pregnancy, primiparous women for the first time feel the movements of their baby - this significant event occurs, as a rule, in the 20th week.

Multiparous mothers identify tremors already at 18 weeks, because the walls of the uterus after childbirth become thinner, and therefore more sensitive, therefore, in the second / third / fourth time, intrauterine movements are better perceived.

By the time the intrauterine movements begin, 20 and 22 weeks should be added during the first and subsequent pregnancies, respectively.

But this method is not very accurate, because girls with different complexities feel jolts at different weeks, a thin woman feels movements within herself already at 15-16 weeks, and a denser one - at 21-22 weeks.

It is worth adding that not all expectant mothers can immediately rightly understand incomprehensible movements within themselves - some confuse this action with an intestinal upset, sorry, or a movement of the abdominal muscles (mild cramp).

You can also determine the approaching birth in the last trimester - by omission of the tummy. This process slightly facilitates the well-being of pregnant women and occurs 2-4 weeks before giving birth.

We calculate the term of birth by ultrasound

Another method for assessing the term of labor is computer diagnostics, or more simply ultrasound. In the early stages (up to 12 weeks), ultrasound can determine the day of conception up to a day based on the size of the head and trunk of the embryo.

Until a certain point (about 3-4 months of pregnancy), all babies develop in the same way, after which the genetic predisposition, especially the nutrition and lifestyle of the mother are already affected.

An ultrasound in the second and third trimesters will have an error of up to 2-3 weeks, because the babies are different and the weight of newborns can vary from 3 to 5 kilograms.

Inexperienced gynecologists can take as a basis the date calculated by the computer, and after the "estimated 40 weeks", begin to take unnecessary measures in connection with the "postponed" pregnancy.

Finally, a gynecological examination on an armchair can be considered in almost the same exact way as ultrasound.

An experienced doctor can determine the gestational age by touch on the size and shape of the uterus, based on which further calculations will be performed, which we determined at the beginning of the article.

It is worth considering that you can not rely on one of the listed methods for one hundred percent, they are approximate and give a result that can vary by 2 weeks in one direction or another. Orientation is based on your feelings and nature, which is never wrong.