How to determine the date of birth by the day of conception. How to find out the date of conception: features, calculation rules and recommendations

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

In a word, even if you can, you should not relax. And within plus or minus two weeks from the appointed time, you need to be ready for childbirth, that is, collect the necessary things, sign an exchange card at the maternity hospital, talk to the doctor who will take delivery, if this is included in your plans.

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

It is important to know!

The expectant mother needs to know that, according to statistics, only 4% of pregnant women give birth on the day that the doctor prescribed for them. That is why the date of birth, which appears on the exchange card, is called preliminary. So you should not worry if the birth began a few days or even weeks earlier. On average, pregnancy lasts 10 lunar months, that is, about 280 days. However, here everything is individual. As a rule, the date of birth is “determined” by the baby himself, when he finally matures and prepares for the birth.

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

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

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

Define ovulation can be done using the website website.

As a rule, the date of pre-delivery is most often calculated from the first day of the last menstruation, adding 280 days to the date. Usually it is this date that the gynecologist writes down on the exchange card. Unless, of course, new circumstances were not revealed during the ultrasound.

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

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

Another way to find out when your beloved baby will be born is by moving the baby. During the first pregnancy, the first tremors of the baby are usually at 18-20 weeks. Those who become mothers for the second time can feel the movements of the fetus at 16-18 weeks. To this date must be added 20 weeks for those who give birth for the first time, and 22 weeks for those who give birth again. This will be the date of birth of the child.

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

Mom - under the nickname KATALINA shares her experience:

“In my first pregnancy, my mother calculated the date of birth by the first movement, and I gave birth right to the day :) Although the terms for menstruation and ultrasound were different. I remember moving at 18 weeks, and she seemed to add another 20 weeks. I know for sure that if you move at 16 weeks, then you need to add 22 weeks, if at 20 weeks, then add 18 weeks, at least that's how it was written in one of the magazines for parents.

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

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

The site for moms knows what moms are worried about for 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 expected due date! A free online service has been created especially for visitors to the Mamapedia website 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 clarify your due date. In addition to the exact date of delivery, the service will also indicate important information about important moments during pregnancy and examinations.

If you are unsure of the exact date of your last period or date of conception, the pregnancy calculator will give you an approximate due date. With a planned ultrasound examination, you will be able to find out the exact date of your birth!

Calculating the date of birth will take a few seconds, and will not make you wait long. You can calculate the date of birth absolutely free of charge and without registration.

Analyzes and examinations

Registration in the antenatal clinic. First appointment with a gynecologist

5-8 weeks pregnant

The doctor will conduct an examination, confirm the fact of pregnancy and draw up your individual examination plan. When examined on a chair, the doctor will clarify not only the fact of pregnancy, but also the condition of the uterine appendages, and will also take all the necessary smears for infections and the epithelium from the cervix for oncocytology (examination for the presence of cells that can provoke cancer). The gynecologist will collect data about your health, ask about diseases of relatives, clarify the features of your lifestyle. The doctor will give you a considerable stack of papers - directions for further tests.

Blood test for hCG (chorionic gonadotropin)

5-8 weeks pregnant

The presence of pregnancy is determined by the level of hCG and the stability of its development is assessed. If necessary, the doctor may prescribe this analysis again, to clarify the dynamics of the growth of this hormone, which can be used to judge how correctly the pregnancy develops at this time.

First ultrasound

5-8 weeks pregnant

The study will clarify the gestational age, see if everything is in order with the fetal egg, and sometimes see the heartbeat of the embryo.

Colposcopy

5-8 weeks pregnant

Special examination of the cervix using a microscope.

Primary laboratory diagnostics

8-10 weeks pregnant

General urine analysis will help evaluate the functioning of the kidneys and bladder (urinary system).
A smear on the flora from the vagina will show the presence of possible inflammatory processes in the pelvic organs, hidden and overt infections.
Examination for urogenital infection. The infection is sexually transmitted and is fraught with serious consequences for the health of the expectant mother and fetus.
General blood analysis, which you pass in the morning on an empty stomach, will help assess the state of your body. It reflects the ability of the blood to carry oxygen, the presence or absence of an inflammatory response, and the body's ability to stop bleeding. This analysis is basic, deviations in it are the basis and starting point for a more detailed examination.
Blood for AIDS, syphilis, hepatitis B and C- this is the detection of antibodies to serious infections, each of which has a significant impact on the health of the pregnant woman and the fetus. If an active process is detected, the question of the advisability of maintaining pregnancy may even arise.
Determination of the Rh factor and blood type must be done once, at the very beginning of pregnancy. If you have a negative Rh factor, you need the future dad to also pass a similar analysis. If the father of the child is Rh positive, it will be necessary to monitor the Rh antibodies in the blood of the pregnant woman throughout the pregnancy, as they can greatly harm the child. Today, technology even makes it possible to determine the fetal Rh factor by its DNA in the mother's blood long before birth.
Blood test for TORCH infection will indicate to the doctor the presence or absence of toxoplasma, mycoplasma, cytomegalovirus and herpes virus in your body. The doctor, if necessary, will select the right treatment.
Coagulogram will help to determine the main parameters of the blood coagulation system, to identify a tendency to bleeding and thrombosis.
Determining the level of glucose in the blood will show the gynecologist how efficiently your pancreas works and whether glucose tolerance is impaired in the body of a pregnant woman.
Feces on eggs of worms.
Blood test for hormones(TSH, T4, AT to TPO, AT (antibodies) to TG) - in order to find out what condition your thyroid gland is in. You may need additional medication support.
Blood chemistry will help to determine the condition of internal organs - kidneys, liver, pancreas.
Blood test for antiphospholipid antibodies- for accurate diagnosis of diseases of the immune system. It is prescribed if there was a history of pregnancy loss.

Visiting doctors

8-10 weeks pregnant

It is necessary to visit a therapist, dentist, otolaryngologist, ophthalmologist, surgeon, cardiologist, endocrinologist.

Electrocardiogram

8-10 weeks pregnant

It will allow you to clarify the absence or presence of problems in the work of the most important muscle in the body, the load on which has increased many times since the onset of pregnancy. If abnormalities are detected on the ECG, the therapist will prescribe an ECHO-KG, which allows you to more accurately determine the degree of cardiac dysfunction.

General urine analysis

at 10 weeks pregnant

Dynamic control of the general analysis of urine will allow you to evaluate the work of the kidneys and bladder.

1st trimester screening

at 12 weeks pregnant

Screening for chromosomal abnormalities and gross malformations of the fetus consists of several procedures:
- Ultrasound, by which the doctor can assess whether the fetus has a visually gross developmental pathology, as well as the presence or absence of signs that may indicate a genetic disease (Down syndrome, Edwards syndrome);
- A blood test that shows if there is an abnormality in certain indicators, which may also indicate the risk of systemic genetic diseases.
- computer analysis of the degree of individual risk of giving birth to a child with a chromosomal abnormality in this couple, taking into account the results obtained from ultrasound and biochemical studies.
- vaginal examination, assessment of the condition of the cervix. This is one of the terms in which ICI can begin to form (isthmic-cervical insufficiency, when the muscles of the cervix weaken earlier than required). Therefore, the gynecologist needs to examine you and evaluate the size and consistency of the cervix. If during the examination CCI is indeed detected, depending on the situation, the doctor will either monitor the state of the cervix in dynamics or suggest hospitalization.

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

Calculate due date online

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

With the help of the online calculator presented on the site, you can easily and simply find out the probable date of the upcoming birth. All that is required of you is to enter the necessary data in the appropriate calculator windows, and the necessary calculations are made by the computer. The principle of the calculation is very simple: the date of the beginning of the last menstrual bleeding and the traditional 280 calendar days are summed up.

The date obtained is an approximation, corresponding to ideal medical indications. The actual dates may vary slightly depending on the individual characteristics of the woman, her state of health and the general course of pregnancy.

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

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

Calculate due date by date of conception

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

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

Calculate due date by ovulation

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

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

Video: How to determine the date of birth.

SUPPLIED
DATE OF DELIVERY

FIRST DAY
LAST PERIOD

Last day of menstruation: Estimated due date: Left before delivery: Zodiac:

The gestational circle is a convenient and simple tool for determining the gestational age, the expected date of delivery, 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 child.

Using our gestational circle is very simple.

If you don't know how old you are, scroll the inner circle so that the green arrow points to the first day of your last period.

green arrow

Wherein arrow "today" will indicate today's date and week of pregnancy, as well as the height and weight of the fetus. Then arrow PDR indicate the expected date of birth.

arrow "today"

If you already know your deadline, then scroll the inner circle so that arrow "today" indicated the week of your pregnancy. Then it will also indicate the height and weight of the fetus, and arrow PDR will indicate the expected date of delivery. In this case, the green arrow will point to the first day of the last menstruation.

arrow PDR

See also:

The easiest and most accurate pregnancy calculator: how to use the gestational circle

From school biology lessons, everyone knows that it takes a woman 9 months to bear a fetus. However, this is a very average value that is not used in obstetrics and gynecology. Doctors monitor by weeks and trimesters. But even these figures cannot be called absolutely accurate. The period from the beginning of the last menstruation directly to childbirth takes an average of 40 weeks or 10 obstetric months. A gestational disc will help you find out the date of birth at the beginning of the last menstruation and track changes.

What does "gestational" mean?

Many hear this word for the first time in a antenatal clinic. The Latin gestatio literally translates as "bearing." Therefore, "gestational" means "pertaining to pregnancy."

Gestational age is calculated from the moment of conception. Determining exactly when this happened is extremely difficult. It may take up to several days for a fertilized egg to implant 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 a relative conditionality of the calculation.

Gestational disc for determining due date

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 of the pregnancy process. With its help, every woman can determine the "X date" at home. This is necessary, since premature and late births pose the same danger. Therefore, it is important to calculate the expected day of delivery and, as it approaches, carefully monitor the signals of the body.

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 baby will be born a few days earlier or later. Normal childbirth is considered between 38 and 40 weeks. But each organism has its own unique characteristics. Some women live 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 interested in what sign of the zodiac and in the year of which animal according to the eastern calendar a child will be born. For some couples, it helps to choose a name.

How is the gestational cycle

With this visual calculator, it is easy to determine the due date and track the height and weight of the fetus during pregnancy. The outer disk 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 disc correspond to the weeks of pregnancy. Also, using a background with different saturation, trimesters are highlighted: the first - from to , the second - from to , the third - from to . Closer to the center is the scale of weight, and at the last level - the growth of the fetus.

There are 3 arrows on the circle: green thin (first day of the last menstruation), EDD (estimated date of birth) and a static “today”. In the center of the circle, basic information is displayed: the beginning of the last menstruation, the expected 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 zodiac characteristics.

How to use a gestational disc to determine the gestational age

The gestational circle is used by many obstetrician-gynecologists in different countries, including Russia. The simplicity of the method allows it to be used by absolutely every woman.

When planning a pregnancy, it is especially important to keep a menstrual calendar. This will help to determine the expected date of birth as accurately as possible. To calculate the gestational age according to the gestational circle, it is enough to move the thin green arrow to the date of the start of the last menstruation. The PDR arrow will indicate the date of delivery, provided that the pregnancy ends at 40 weeks. Using the “today” arrow, it is easy to track the average height and weight of the fetus for each week.

For example, the last menstruation was from 12 to 16 December. For the calculation of the gestational circle, only the first date is important - December 12. Set the thin green arrow to this number. Twisting the arrow, pay attention to the center of the circle. This is much more convenient than peering into divisions. The “today” arrow 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. You need to prepare for childbirth within 1-2 weeks from September 18th.

What should a woman do if she does not know the date of her last menstrual period?

To independently determine the date of birth of a 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 released in the body of a woman after implantation of the embryo in the uterus at 4 obstetric weeks. From this point on, 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 the hCG hormone in the body. To obtain reliable results, you need to try again in a week if menstruation does not begin. A weakly pronounced second strip can appear in women taking hormonal drugs, regardless of pregnancy.

A home test only shows the presence of pregnancy. According to the result of a biochemical blood test, its duration is determined. Don't put off checking. Analysis for hCG 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 is known, the gestational circle can be used to calculate the date of delivery and determine the size of the fetus. To do this, just set the “today” arrow to the mark corresponding to the current date.

For example, it's week 9. At this stage of development, the embryo has reached 23 mm and weighs 2 g. The expected date of birth is September 9. The green arrow indicates the approximate date of the last menstrual period.

Errors

Bearing a fetus is a complex process that each woman proceeds in a special way. Moreover, the course of the first pregnancy does not mean that the next ones will follow the same scenario.

The pregnancy calculator allows a certain error. In addition, when setting the initial data, errors are not ruled out. The accuracy of the calculation depends on the individual characteristics of the organism. The pregnancy wheel 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 embryonic terms.

In addition, the error can be provoked by inaccuracy in determining the embryonic period. The spermatozoon is able to remain 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 expected date of birth often reaches 2 weeks. Ultrasound gives more accurate results, although the method of calculating the beginning of the last menstruation is recognized worldwide as one of the best.

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

You can see 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, every day is important. At the same time, 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. Directly during this period, the birth of a new life could not occur. The moment of conception depends on ovulation and varies within a couple of weeks.

With a standard menstrual cycle of 28 days, ovulation occurs on the 14th day. 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 by different methods do not match

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

In official medicine, it is believed that embryos develop in the same way during the first trimester. On ultrasound, the gestational age is determined according to the table of correspondence between the size of the fetus and a certain period of development. For example, the calculation for the last menstruation shows the result of 12 weeks, and the diagnostician calls 11 weeks. More reliable is considered to be the period set during the first ultrasound. In this example, the difference is due to early ovulation, but it can be late. For the doctor, the result of an ultrasound examination is a priority.

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

The gestational circle gives an idea of ​​how the unborn child 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 and 21 weeks is an average of 71 g. It is interesting for every woman 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 child was 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 feel the conception, or from the first weeks there will be obvious signs in the form of a heightened sense of smell, morning sickness, etc. It is not uncommon for a woman to find out about pregnancy only by her enlarged belly.

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 that are 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 goes according to plan, there are times when extra care must be taken. If at any stage of pregnancy a woman feels severe discomfort, burning, or even unreasonable anxiety, you should visit a doctor.

When to be extra careful

Critical periods coincide with the phases of active growth of the embryo and placenta. The most dangerous weeks are the following:

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

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

The period from to 22 weeks is considered the most important. At this time, the unborn baby is most active. The biggest risks to the life of the fetus and the health of the woman 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, but it is not yet able to survive separately from the mother's body. Causes of preterm labor may include placental abruption, infections, and isthmic-cervical insufficiency. To prevent this, you need to follow absolutely all the doctor's instructions, take care of your own health and eliminate stress.

There are no critical periods on the gestational circle. This is due to the fact that they do not have to be difficult at all. The more you focus on the dangers, the stronger the destructive effect of stress. You can use the pregnancy wheel 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 approaching date of birth.

Description

The 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, similar to a watch dial, the inside of which can be rotated, setting one or another hand in the desired position. For example, by setting a thin green arrow so that it points to the first day of the last menstruation, you will determine the date of future births by the arrow "PDR", and by the arrow "today" you will find out what week of pregnancy you are now, and what is the height and weight of the fetus on present day. The Pregnancy Wheel can also be used in other ways. For example, if the birth has already taken place, then you can set the arrow "Ed" (estimated date of birth) so that it points to the day of birth. Then a thin green arrow will show you the date on which you had your last period 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.