How to set the due date for the last menstruation. Calculation By date of conception

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The expected date of birth begins to interest a woman from the first day she found out about her situation. The approximate birthday of a child can be calculated in several ways, but none of them can boast of 100% accuracy. Many factors can influence the pregnancy process, and delivery is often premature or late.

What determines the time of birth

Even in a healthy woman carrying a healthy baby, the date of birth may deviate from the approximately calculated period and depends on:

• on whether she gives birth in or;
• from the duration of the menstrual cycle;
• from heredity and other individual characteristics of the mother;
• on the characteristics of the intrauterine development of the baby;
• on how many babies are in the uterus.

In the presence of chronic diseases in a woman, a violation of the intrauterine development of a child, acute diseases or injuries during pregnancy, the delivery date may significantly deviate from the planned date.

Ways to determine the date of birth

The most common methods for determining the estimated due date are as follows:

• by the date of the last menstruation;
• by the time of ovulation;
• by date of conception;
• by ultrasound;
• according to the size of the uterus;
• by the first movement of the fetus.

Let's consider each in more detail.

By last menstrual date

The date of birth by menstruation is the most common way to determine.

It has been used by obstetrician-gynecologists for many decades because:

• not all pregnant women know the time of the last ovulation or the date of conception with regular sex life, but everyone remembers when they had their last menstruation;
• this is a pretty accurate method.

To determine the day of birth, it is necessary to remember the first day of the last menstruation, add 1 year to this date, then subtract 3 months, and then add 1 week. The calculated date will be a guideline for the expected birth. Another way to determine: add 9 months and 1 week to the first day of the last menstruation.

By time of ovulation or expected conception

The method of calculating the date of birth by the date of conception can be used with a planned pregnancy, when a woman specifically calculated the days of ovulation and knows them. It is during this period that conception occurs. 266 days are added to the first day of ovulation and the date of delivery is calculated according to the calendar. This method is called embryonic.

By date of intercourse

This method is convenient to use with irregular or rare sexual activity. In this case, the woman knows which day in her life was decisive. Everything is very simple - 266 days are added to this date. This method is closer to the embryonic one. The due dates calculated by these two methods may differ by only a few days because the date of intercourse and conception often do not coincide. Not everyone knows that some spermatozoa are able to live in a woman's body for up to 9 days, waiting in the wings.

According to ultrasound

Using ultrasound, the doctor can determine the approximate date of birth, based on the established age of the fetus. Most precisely, this is established in the first trimester of pregnancy. In the future, there may be an error from several days to 3 weeks.

According to the size of the uterus

An old medical method was an approximate determination of the gestational age and, accordingly, the expected birth according to the size of the uterus. As in the previous case, it is possible to more accurately set the time of delivery in the early stages of pregnancy. In the future, the size of the uterus depends on many factors (the size of the fetus, the amount of water). In addition, this method is only suitable if there is 1 child in the uterus.

By the first movement of the fetus

An old folk way of guessing the date of birth is to move the baby. After the disappearance of menstruation, a woman could only suspect that she was pregnant, but when the fetus began to move, this was a 100% sign.

The woman added 20 weeks to this date and could quite accurately guess the due date with minor errors. It should be borne in mind that multiparous are already familiar with the feeling of fetal movement in the uterus and they, as a rule, feel it 1-2 weeks earlier than primiparas.

Calculation efficiency

The exact day of delivery cannot be determined, because the period from 38 to 42 weeks of pregnancy is considered the normal period for delivery. Thus, as many as 28 days can be considered the date of delivery "at term". However, in the normal course of pregnancy, different methods of calculation approximately coincide and circle around the same date in the range of +/- 14 days.

Gynecologists officially still use calculations to determine the possible day of birth according to the last menstruation, so this period is called obstetric. This method in about 20% of cases guesses the date of birth with an accuracy of +/- 5 days, and this is a rather high percentage. The exact coincidence of the date of birth and obstetric period is about 5%.

How do the features of the menstrual cycle affect the date of birth

Regardless of the duration of the menstrual cycle, the obstetrician-gynecologist applies the formula for calculating the term of childbirth by the date of the last menstruation. Accordingly, women with a short cycle and a long one will have the same due date. However, the date of ovulation is different for them, therefore, the conception and the term of delivery will be different.

With a short menstrual cycle (24 days) ovulation occurs on the tenth day. Fertilization occurs on the days of ovulation. Therefore, the actual due date in women with a short cycle will be expected a week earlier. The date of birth is calculated using the following formula: the date of the first day of the last menstruation plus 1 year and minus 3 months.

Long cycle (35 days) ovulation occurs on the twenty-first day. Childbirth will be a week later than the gynecologist calculated. A woman can calculate the date in this way: the date of the first day of the last menstruation, plus 1 year, minus 3 months, and plus 14 days.

Calculate the date of birth with an irregular menstrual cycle with large jumps should be according to the classical formula.

When you can not use the obstetric method of calculation

The obstetric method of determining the date of birth by the last menstruation is the most common.

But it is not possible to use it in the following cases:

• when pregnancy occurs immediately after a previous birth, and menstruation has not yet occurred;
• with severe menstrual irregularities, when the interval between menstruation can be more than a few months, as is the case with menopause or various female diseases, for example, polycystic ovaries or hormonal disorders.

What are the deviations from the deadlines?

The bearing of a child lasts 9 calendar months, or 10 lunar months (28 days each), or 280 days.

Births are classified into urgent, premature and late:

• Childbirth at 38-42 weeks is a normal period. Statistically, 70% of mothers give birth in the range of 39-41 weeks. Primiparas often give birth 1 week later than the normal due date. But with repeated births, on the contrary, women often give birth before 39 weeks.
• Childbirth after 42 weeks is late. The child is considered to be overdue. There are about 9% of such births.
• Childbirth before 38 weeks is premature. The viability of the baby depends on the gestational age at delivery. The closer this period is to normal, the better.

Everything is individual, and in case of premature birth, a completely healthy and mature baby can be born, more often this happens for a period exceeding 35 weeks. If the baby is underweight - less than 2500 grams, he will be considered premature.

The second degree of prematurity is established at the term of delivery from 32 to 35 weeks and the weight of the child is less than 2000 grams. However, he also has a very high chance of "ripening" and gaining weight after birth without the use of hardware life support.

In case of premature birth from 28 to 31 weeks, the child will be with prematurity of the 3rd degree and low body weight (from 1000 to 1500 g). Such children are successfully nursed in perinatal centers.

At the birth of a child for a period of 22-28 weeks, he will have a 4th degree of prematurity. The baby has extremely low body weight and undeveloped lungs. There is no surfactant substance, which ensures the free breathing of the child.

Previously, a fetus weighing 700 g was considered viable, now - with a mass of 500 g or more. Such children are nursed in intensive care units using special plastic transparent boxes - incubators, which provide the necessary temperature, humidity and sterility of the environment. The baby is connected to a ventilator, feeding is carried out intravenously or through a tube, the necessary drug therapy is provided.

A child born before 22 weeks will be unviable due to severe immaturity. Such babies are currently not able to leave the medicine.

Causes of preterm labor

The total share of all preterm births accounts for about 10% of cases. The cause may be maternal or fetal pathology, or a combination of various factors.

The most common of them:

• Social and domestic - smoking, alcohol abuse, drug use, stress, extreme physical activity, malnutrition and hypovitaminosis.
• Pathology of the uterus - the consequences of abortion, other operations on the uterus, hypoplasia, endometritis, endometriosis.
• Pathology of ongoing pregnancy - placental abruption, oligohydramnios, premature rupture of amniotic fluid, inflammation of the membranes, multiple pregnancy,.
• Mother's diseases - diabetes mellitus, hypertension, rheumatism, bronchial asthma, severe anemia, mental disorders, etc.
• Multiple anomalies in the development of the child, incompatible with life, at present, the latter is rarely the cause of premature birth, as women try to terminate their pregnancy in the early stages for medical reasons.

In the presence of such risk factors, a woman should be especially careful, since she has a high risk of having a premature baby. She may have to spend some time saving.

Determining the expected date of delivery is an important task. But in any case, the calculated period is approximate. It depends on many reasons. Therefore, with a long gestational age, a woman should listen to herself and expect childbirth, starting from the 37th week of pregnancy, or even earlier.

Useful video about calculating the due date

Hello dear readers! Today I propose to talk on a very intimate, but important topic that worries almost every expectant mother - “How to correctly calculate the due date?”. The birth of a child is the most important event in a woman's life. For example, I was waiting for him, and at the same time I was afraid. Then my gynecologist told me several ways that helped me accurately calculate this date. I am happy to share this information with you. Are you already interested? Then maybe we'll start.

We determine the day of birth by the day of conception

Determining the exact date of the birth of a child by the date of pregnancy is the most common method used by many expectant mothers. We add 9 months to the estimated date of conception, and you're done! Did you also calculate the time of birth using this method? I hasten to upset you - these are wrong calculations! The thing is that the process of bearing a child lasts 280 days, not 9 months.

Your personal ovulation calendar will help determine this important day. The thing is that the moment of fertilization of the egg sometimes does not coincide with the time when the decisive sexual intercourse took place. Did you know that spermatozoa can live in the female body for up to 7 days, and stubbornly “wait” when fertilization can be carried out?

Most often, the day of ovulation is the day of conception. It is enough to add 280 days to it, and you will know when the day "X" comes.

How to correctly calculate the due date

If you were unable to make the appropriate calculations for the date of conception, use your personal menstruation calendar to calculate the baby's birthday. Every girl has it. Is not it? Any gynecologist will tell you that the regularity of the menstrual cycle is very important.

Doctors calculate the time of birth using the special Naegele formula. This method is only suitable for those girls whose menstrual cycle works like clockwork and lasts 28 days. Let's try to use the formula together on a specific example.

The general wording sounds like this - from the first day of the cycle you need to subtract 3 months and add exactly 7 days. For example, my last period started on September 28th. I subtract 3 months from this date - it turns out June 28. We add 7 days, and we get the deadline - July 5th. This is a very simple but effective way. Do not believe it, but the period I calculated exactly coincided with the birthday of my baby.

Ultrasound is the best way to determine the day "X"

Medicine does not stand still. Gradually, new equipment appears that allows for the most accurate studies of the body of a future woman in labor. With the help of ultrasound, the gynecologist can determine the size of the fetus, and from these data set the EDD (estimated date of birth).

I had different periods for menstruation and ultrasound, so I had to use another method, which I will discuss below.

In order for the results of the survey to be as accurate and truthful as possible, you need to perform. If you go to the doctor too early, he won't be able to see anything because the fetus is very small in early pregnancy. The ideal time to determine the EDD by ultrasound is 10-14 weeks.

The main thing is not to miss this moment, because then the baby will begin to actively grow and develop, and its physiological changes will depend solely on the individual characteristics of the organism. If you make an appointment for the first ultrasound examination in the 2nd or 3rd trimester, the gynecologist will not be able to accurately determine the EDD.

The baby stirred in the stomach - it's time to calculate the exact date of birth

Did you know that fetal movement can also be used to recognize the EDD? It is about this method that I promised to tell you in the end. Well, promises must be kept! Of course, this method can be considered rather approximate and inaccurate, but it has its place. The thing is that a girl who gives birth for the first time feels the movement of the fetus a little earlier than a mother with experience.

Be sure to remember the day when you first felt that the baby inside you began to move. You can use one of these methods:

• If you will give birth for the first time, add 20 weeks to this date;
• A girl who already has children must add 24 weeks to this date.

The method for determining the PDR by the first movements of the fetus is considered the least accurate.

If you had an irregular cycle before conception, be sure to notify your gynecologist about this. A very unpleasant situation happened to my girlfriend during pregnancy. The thing is that her menstrual cycle is not 28, but 40 days. Doctors did not take this fact into account, and calculated the date of the start of contractions, which turned out to be incorrect. As a result, “Day X” came, and her labor activity did not begin.

The doctors were about to administer drugs for stimulation, but she managed to point out an error in the calculations in time. That's how useful it is to independently calculate the time when the child will be born! Thank God my friend and her baby are fine. The birth was easy, but she was frightened in earnest. Now you understand how important it is to correctly calculate the PDR? Your health and the life of the newborn may depend on this.

Well, my dear future mothers! I wish you patience, peace and good health. Childbirth does not need to be afraid, and then they will pass quickly and easily. Perhaps you know other methods for determining the date of birth of a child? Share them in the comments, and be sure to visit our blog more often. There are many more interesting and useful things waiting for you.

Use our EDD (Estimated Due Date) calculator to calculate your baby's estimated due date. The calculation can be made by the date of conception, or by the date of the last menstruation. Select the appropriate option and enter the original date. As a result of the calculation, you will receive the cherished date, as well as an accurate pregnancy calendar with comprehensive information about the development of the fetus and medical indications for each week. Calculation results can be saved to email or printed.

EDD Calculator - Estimated Date of Delivery
with pregnancy calendar

Calculation option:

If you know the exact date of conception of the child, use the first option. Or choose the second option, the estimated date of delivery will be calculated automatically, according to the date of the beginning of the last menstruation.

Start date of last menstrual period:

Cycle duration:

On average 28 days. If you don't know the exact length of your cycle, leave the default value.

28 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 days

Conception date:

Women tend to get as much information about their new condition as possible by learning about pregnancy. It is also important to find out how to calculate the date of birth and the sex of the child, whether it is worth using an online calculator for this, what features and algorithms it includes. All this and much more is discussed in our article.

Calculation of the due date - principles and algorithms

You can use several options to calculate the exact date of birth: an online calculator, your own calculations, the result of a doctor's examination. But whichever option is chosen, their principles and algorithms are very similar.

Determination of the term by the date of conception

The easiest way is to make a weekly pregnancy calendar and calculate the date of birth if the girl knows the date of fertilization. Usually, difficulties arise with this, because a couple who decides to have a baby tries not to miss any of the favorable days. Therefore, if it is not possible to calculate the due date by the date of conception, you can try to determine it yourself. To do this is not at all that difficult.

To do this, it is worth remembering how the process of childbirth proceeds in the body of a girl:

1. Bubbles form in the ovary immediately after menstruation. One is ahead of the others in growth and speed of development. It is in it that the female cell appears. The remaining follicles gradually disappear.
2. The cell reaches its peak of development and is ready to function, breaks through the follicle and is released. Her path lies in the direction of the uterus. Here, in the genital tract, fertilization by sperm must occur under favorable conditions. This moment will need to be known in order to calculate the date of birth by the date of conception.
3. The fertilized cell continues the journey and completes it with implantation in the uterus. This happens only 7 days after meeting with the male cell.
4. Under the condition of normal fixation, the fetus begins its growth and development. This process is promoted by progesterone, which produces the corpus luteum. The latter acts as a temporary gland, which grows on the wound from the rupture of the bubble. It always appears, but if fertilization does not happen, it structurally collapses by the day of the next menstruation, leaving a small scar on the ovary.
5. There are changes in the structure of the mammary glands under the influence of progesterone. Signs of a new situation begin to appear, which is why the woman begins to look for ways to calculate the date of birth, draw up a calendar using a calculator, what tests to take and when to visit your doctor for the first time.

Ovulation and date of conception

So, in order to make a pregnancy calendar and calculate the date of birth, you need to calculate the day of fertilization of your cell. How to do this, subject to the presence of daily sexual intercourse, for example? At first, it is worth remembering that conception occurs only at the moment when the cell has already freed itself from the follicle shell and has passed into the sexual path. Those. it is very easy to calculate the due date by the date of ovulation. As you know, this process is very short and is usually equal to a day, which is why the error in the miscalculations is practically eliminated.

How to calculate due date from last period

If the girl does not know the exact day of ovulation, it can be calculated based on her cycle readings. You need to look at the calendar and calculate the date of birth according to the last menstruation.

Data for accurate calculation

The following parameters need to be assessed first:

• Cycle duration. Calculate the number of days between the indicated dates of menstruation for the last few periods. The standard is 28 days, but there are also values ​​​​in the range of 21-33 days.
• Systematic. Compare the received numbers with each other. Normally, they should be equal, with a maximum deviation of 1 day. In such a situation, there will be no problems with how to accurately calculate the date of birth. There are also failures, when in one month there is suddenly a shift for 1-2 weeks. This is caused by stress, illness, the use of hormone-containing drugs, climate change, etc. You don't have to worry, it's normal. If the cyclicity is broken and every month the terms differ by 5 or more days from each other, the rhythm is recognized as irregular. This is not scary, just calculating the gestational age and the date of birth will be an order of magnitude more difficult. If such failures have not occurred before, it is better to consult a gynecologist on the reason for identifying possible problems.
• Duration and characteristics of menstruation. Normally, they should be of the same type in structure, abundance and duration every month.

Ovulation in the menstrual cycle

Knowing the parameters that the calendar gave us, it is not difficult to calculate the date of birth if you identify the day of ovulation. It is calculated when you need to calculate the date of birth by menstruation, based on such knowledge regarding the duration of the flowing phases in the female cycle:

1. The time of follicle and cell generation is 11-17 days. It differs significantly in women due to the different content of hormones in the body and their balance. The standard is 14 days, but it is possible for girls whose cycle is unchanged for a long time and is equal to 28 days.
2. The release of the cell and its path to the uterus. If spermatozoa are not found along this path, it will last only a day. Rarely, vital activity can be higher - up to 2-3 days, usually, it dies after 12 hours. That is why pregnancy, to calculate the date of birth by which would remain the last unresolved issue for the girl, the date of ovulation must be identified as accurately as possible in order to assign a productive act.
3. The functioning of the corpus luteum in the absence of a fetus ends exactly after 14 days. This criterion is the same for everyone. Very rarely, it can be 12-13 days.

The last number, which is equal for all girls, is reliably known, and therefore ovulation is considered according to it. The formula looks like this: subtract 14 from the duration of the monthly process. The result obtained must be counted from the previous menstruation and marked on the calendar. This is the date of ovulation, which is the moment of conception, because. on other days it is not possible due to the lack of a finished cage. Now it is already easy even to prescribe a birth calendar and calculate it according to the date of conception, revealed in the described way.

Methods for determining cell yield

• Tests. After using the strip according to the instructions (dipping it in urine for a few seconds or holding it under a stream), you need to look at the change in the color of the reagent. It shows the concentration of luteinizing hormone, which reaches a maximum when the follicle ruptures.
• Microscopes. These are reusable devices that allow you to see the pattern of salts contained in saliva. It gradually changes, acquiring the features of a fern by the day the cell appears. It will be enough to calculate the day of birth by the date on which it manifested itself most clearly.
• Allocations. It is known that during the development of the follicle, the vaginal mucus has a dense structure and does not come out. And by the time of the "birth" of the cell, it liquefies and is excreted in a very abundant amount. In structure and color, it is similar to egg white. observed until cell death.
• Pain. Unpleasant sensations are felt in the direction of the ovary. By tearing the follicle, the cell creates an ordinary wound on it, which causes a little pain. Relying on your own feelings and remembering the exact date of the onset of pain, it will be easy to calculate the date of birth by conception.

Prediction of the gender of the child - what you need to know

We figured out how to correctly calculate the date of birth, first by identifying the exact day of fertilization. Now it remains only to count 40 weeks from the date, making notes on the calendar. Sometimes girls want to not only calculate the date of birth, but also find out the sex of the child early. This can be done by comparing the date of intercourse with ovulation:

• The act fell on the date of ovulation or a day later - a son is expected. This is due to the characteristics of male spermatozoa with a Y-chromosome, which are much faster than X-type cells. Y will overtake a female cell many times faster, leaving no chance for slow brothers. Having identified pregnancy, it is very simple to calculate the date of birth and the sex of the child according to the principles described above.
• The act happened in 1-2 days - the maximum probability of conceiving a daughter. This is explained by the fact that Y-cells die in a day, being in the genital tract, and therefore do not wait for the appearance of the female. X cells last up to 3 days, and therefore, although they are very slow, they will already be waiting for the female by the time she appears in the genital tract. When compiling a calendar to calculate the date of birth and the sex of the child in such a situation, one must also take into account the day the cell appeared, despite the fact that the act was earlier.

Thus, regardless of the fulfillment of the conditions for “receiving” a baby of the desired gender, it will be necessary to calculate the date of birth according to the day of conception. Indeed, without the presence of a female cell in the pathways, spermatozoa do not fertilize anyone.

Calculator - how to calculate the due date online

Calculation by date of conception or last menstruation

Therefore, today there are two options for filling in data:

• calculate the date of birth by conception: the calculator counts the standard of days of pregnancy from the day known to the girl;
• calculate the date of birth by menstruation: the calculator determines the moment the cell appears, therefore the formula requires a cycle length parameter. If the girl does not know him, it is recommended to leave 28 days. But in this case, an error is possible.

Pregnancy calendar is a useful feature

As a result of the calculation, the girl receives a specific date of the expected birth. But that's not all. Our service has an additional function that allows you to calculate the date of birth and pregnancy by week at the same time. At the same time, the girl receives a table painted for each week of pregnancy with an indication of her dates, containing such interesting and useful information:

• Fetal development: at each stage, the embryo undergoes certain changes, because it is constantly developing. You can find out when his muscle tissue begins to grow, internal organs form, and when he begins to hear.
• Medical indications: the baby's body at each stage, based on the characteristics of the formation, requires different microorganisms, which are prescribed in the tablet. The girl also learns when to expect toxicosis, discomfort, heartburn, how to protect yourself from them without harm to the crumbs.

After the girl has calculated the date of delivery and by weeks, having received a detailed action plan, you can save it to yourself in electronic form by clicking on the "send by mail" icon. It is also available to print the table to have it at hand.

Medical indications - tests, ultrasound, etc.

By using the pregnancy calculator to calculate the due date on our website, you also get data on the required dates for tests and ultrasounds. This will allow you to control the actions of the doctor and better prepare for visits and examinations. Calculating the due date online is a simple way, due to which the girl does not need to make calculations on her own, and in return she receives maximum useful information on her particular case.

Irregular Cycle Calculation

Some difficulties await ladies with irregular processes, then there may be difficulties in detecting ovulation. They can only calculate the date of birth by the date of conception, the online calculator in this situation will give the correct answer. If they want to calculate the date of birth based on the last menstruation, the calculator may be wrong, because the result depends on the length of the cycle, which is always different for a girl.

Determining the date of birth by a doctor

Many are sure that only a specialist observing the patient is able to calculate the exact date of birth. But it is worth remembering that it is based in its readings on the same data as the above methods. The doctor, in the event that he did not observe the girl before pregnancy, will ask her for the following data:

• First day of bleeding;
• Cycle duration;
• systematic;
• The presence of failures in the rhythms and deviations.

Based on these criteria, he will calculate and determine the expected date of delivery. Most likely, this date will coincide with the date of birth, which can be calculated from the date of conception online. There may be a small error of 1 day due to the "human" factor or unaccounted for moments.

Ultrasound calculation accuracy

If the doctor wants to calculate the date of birth by ultrasound, the calculator is more likely to lose. Indeed, in the study, he is able to see the size of the embryo and compare it with the standard. However, a mistake is also possible here, because each organism develops in its own way, and the embryos can differ somewhat in size in girls at the same time.

Determination and stimulation of ovulation

Therefore, it is only possible to calculate the correct date of birth mathematically, based on knowledge of the day of fertilization or by finding out the exact date of ovulation. If a girl has problems with this, she should go to the hospital already at the planning stage so that the doctor can control the process of egg development on ultrasound. Already from the 5th day after menstruation, examinations begin with a frequency of once every two days. When the cell exit is approaching, ultrasound can be prescribed daily. Having found a burst follicle or a day before, the doctor will inform the patient about the most successful moment for fertilization.

From the video you will find out on which day you need to do an ultrasound to find out if the follicle is maturing

A similar scheme of examinations occurs if the girl has problems with cell reproduction (the follicle does not develop or burst). This is due to the insufficiency of the hormone estrogen, and therefore it is administered forcibly, through a special course of drugs.

With such strict observation of the stages of cell development, in order to accurately calculate the date of birth, a calculator is not required. After all, the girl and the doctor will reliably know the day of fertilization. During follow-up, the doctor will trace the moment of implantation of the fetal egg. A woman will not need to perform a test or donate blood, because the ultrasound will show the fact that the embryo is fixed, which guarantees pregnancy, and calculating the date of birth by the date of conception for a doctor, knowing all the facts, will not be a problem.

conclusions

The expected date of birth, which can be calculated in several ways, will give the girl an accurate idea of ​​​​the duration of the wait for her little “miracle”. You can use any of the above methods or try all of them. Usually, the deviations between them are no more than 1-2 days. We recommend using our calculator and calculating the date of birth by menstruation (or by conception) online. In this case, in addition to the expected date of birth, in addition, the expectant mother will receive a kind of guide to action and tools to control the development of her baby by weeks.

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 obvious signs will appear 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 cycle. 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 the expectant 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.

As soon as a woman finds out that she is pregnant, her life changes instantly. Someone perceives this news with unconditional joy, others - with surprise and confusion. But absolutely everyone needs to know when the baby will be born. There are quite a few ways to calculate that very happy day. The most famous, commonly used and affordable is to calculate the date of birth by menstruation, the calculator allows you to do this automatically. To find out when the baby will be born, you must enter the number when the last menstruation came.

Enter the date of the first day of the last menstrual cycle (monthly):

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

How accurate is this calculation? The only answer that can be given is more or less. After all, pregnancy is a highly individual process. Each child develops according to its own laws. However, the deviation of the calculator by, say, a week is acceptable. But if childbirth does not occur after 10 or 14 days from the planned date, then such a pregnancy is called post-term. A significant advance of events is also a pathology. And so, about when childbirth is the norm, what premature and late childbirth means, and how to calculate their term in different ways - we will talk in this article.

Calculation of the term of delivery by menstruation

Calculating the date of birth by menstruation is the easiest. No additional equipment, complex calculations, attention to sensations are needed. The approximate date can be calculated with a calculator, as well as simple independent calculations. To the number in which the last menstruation began, you must add 7 days, and then subtract 3 months. So, for example, menstruation began on September 1, 2016. Adding a week, we get September 8th. We subtract three months, change the year to the next one and get the estimated date of the happy event - June 8th.

A common question is why such a reference point? After all, conception occurred later (or earlier), and what does menstrual bleeding have to do with it? From this date, the so-called obstetric gestational age is considered. The stage of life of the egg is taken into account from the moment it begins to develop until maturation (ovulation). According to this method, the process of waiting for a child lasts 10 months, 40 weeks, or 280 days. This is two weeks more than when calculating the term for the birth of a baby by conception.

This technique is used by all obstetricians and gynecologists. Despite its relativity, it is the most accurate and convenient for orientation. It is she who is looked at first of all when the pregnancy is delayed or, on the contrary, tends to be resolved earlier.

You can calculate the treasured day at any moment of waiting for the child. The main thing is that a woman remembers when her last menstruation before pregnancy began.

Other calculation methods

How to correctly calculate the due date? The answer is quite simple - by all known methods. In the birth chart of each woman, the estimated date of the birth of her baby, determined by several methods, is indicated. Reliable (except for the "menstrual" method) include:

• by ovulation;
• on ultrasound diagnostics;
• by registering the first movement;
• by objective examination.

Definition by ovulation

Calculating the date of birth by menstruation is as simple as calculating ovulation. Only in this case, not the first day of bleeding, but the middle of the cycle is taken as the main reference point. If a woman lives on a cycle of 28 days, respectively, the countdown goes from day 14. The baby will be born in approximately 38 weeks.

But again, the question arises: what to do if the “same” sexual intercourse did not occur on the day of egg maturation? Is it possible then to calculate the date of birth by ovulation?

Yes. The thing is that the spermatozoa, getting into the body of a woman, "wait for the right moment." If sperm reflux has occurred before this very moment, then the germ cells will wait. They are able to survive in the conditions of the female body for 2 to 4 days (on average). But if seminal fluid enters the vagina after ovulation, then pregnancy probably will not occur. It is on such calculations that the calendar method of contraception is based.

However, life cannot be ordered when to be born, and when not. There are cases when spermatozoa survived for a week! It happens that pregnancy occurs during menstrual bleeding (the child is born, of course, by Chuck Norris. Therefore, this technique also cannot claim to be exclusively truthful, although it works in most cases. Most often, the estimated day of delivery is calculated from ovulation only once, at the initial examination Later, the exact date of maturation of the egg is forgotten, and there is a risk of error.

Definition by ultrasound

It is worth noting that a specialist in ultrasound diagnostics cannot reliably determine the gestational age. Nonsense? Not really. The fact is that the doctor can only state the fact: the development of the fetus corresponds, for example, to the 20th week of pregnancy. Later, this conclusion is compared with the estimated period calculated in other ways. It is concluded whether there is a lag in the development of the fetus, whether it is possible to diagnose a missed pregnancy, or everything is in order.

Accordingly, it is also impossible to reliably calculate the date of birth by ultrasound. The exception is early dates. In the period up to 3-3.5 months, all embryos develop in the same way, they do not have individual characteristics (if we are talking about the norm). Only later, some begin to grow faster, adopting the constitutional properties of their parents, others - more slowly. That is why in the first weeks of pregnancy, the end date can be set quite accurately with the help of an ultrasound machine.

Objective definition by a doctor

An experienced obstetrician-gynecologist can predict when a woman will give birth. At the beginning of the consultation, he determines the approximate period for menstruation, and then conducts an external examination. The pregnant uterus increases in size every week, grows, reaching certain external landmarks. These include, first of all, the pubis and navel. Contrary to philistine logic, the bottom of the uterus is not from below, but from above. Imagine an inverted bag or a normally oriented half-deflated balloon. The uterus reaches the named "reference points" precisely with its bottom. It is well felt through the skin and abdominal muscles, especially in fragile girls.

Already from the end of 3 months it is possible to determine the height of the fundus of the uterus. At first, it is hidden behind the pubis, by 14 weeks it protrudes from behind the womb, tending to the navel, and reaches the middle of the distance at 16 weeks. Exactly under the navel, it is located in the period of 6 months (24 weeks), increasing more and more.

The accuracy of this technique is difficult to assess. On the one hand, the patterns of changes in the size of the uterus are the same for everyone. On the other hand, firstly, each doctor has his own hands, and he feels them differently than another doctor. Secondly, the degree of uterine distension largely depends on the size of the fetus. And it can be different for different women. It should also be noted that at later stages of pregnancy, such a determination is difficult due to the significant stretching of the organ and the high variability in the size of the fetus.

Definition by the first stirring

Each woman can independently calculate the date of birth by menstruation. And this does not require, as already mentioned, special attention to your body - it is enough to keep a menstrual calendar accurately. But the method that proposes to calculate the approximate term of delivery, focusing on the sensation of stirring, asks for a careful attitude to your feelings.

It is believed that with the first movement of the fetus in the womb, the strength of the bond between mother and child is strengthened a hundredfold. Women finally realize that there is a new life inside them. In this regard, in most cases, the very first movement of the fetus is of great importance.

Normally, the baby begins to move as early as 3 months. However, he is still too small for his mother to feel his movements. True, sometimes, I must say, suspicious ladies confuse the processes of digestion with the movements of the crumbs. But a woman really begins to feel the “presence” of a baby at 20 weeks, if she gives birth for the first time, or at 18, which refers to multiparous. It is from this period that in the birth exchange card, at each visit of a woman to a consultation, it is indicated whether she feels the movements of the fetus.

• 20 weeks if firstborn is expected;
• 22 weeks if the woman has more children.

Thus, in the early stages, the estimated number of an important event is best determined by ovulation or by ultrasound. In the second trimester, the doctor will best deal with this task during the examination. But by the second half of pregnancy, you need to listen to the movements of the baby.

Calculation of due date after IVF

In vitro fertilization refers to assisted reproductive technologies. To carry out this procedure, a couple is prepared for a very long time. A man and a woman must pass a lot of tests, cure all somatic (“non-sexual”) pathologies, and lead a correct lifestyle. In addition, before the egg retrieval procedure, the woman's ovaries are stimulated with hormonal therapy.

Doctors are not guided by monthly periods, they “set” their own cycle. At the same time, not one or two, but a dozen eggs mature. This procedure is called controlled ovulation. This means that her date is known exactly, because. triggered by drugs. In this case, it is most correct to consider the moment of the appearance of a new person precisely from ovulation. The date of embryo replanting is known for certain. Usually, pregnancy occurs 12-14 days after the transplant procedure. Thus, the calculation can be carried out from this day.

The fact is that there are no features of the waiting period for the baby in this case. The only difference is that such pregnancies are most often multiple, so they are resolved a little earlier.

Date Calculation for Irregular Cycle

In this case, this method of calculating the treasured day is not suitable. You can try to determine by the date of ovulation - the average duration of the menstrual cycle per year is taken as the basis, and the time of egg maturation is calculated from it. However, this answer is quite far from the truth. Therefore, a combination of different options is considered the best way - focusing on ultrasound and the approximate gestational age.

But if the cycle is regular, but lasts more than 28 days, then there should be no difficulties. Ovulation somehow occurs in its middle, so “day X” is simply calculated, and further calculations are made on it.

When is the normal time?

Term delivery is a delivery that occurs between the 37th and 41st (40 weeks and 3 days) weeks of pregnancy. Moreover, in obstetric practice, the main method is the calculation of monthly. The term "urgent" is used in this case not in the sense of "emergency, urgent", but as a birth that occurred "on time".

This means that a healthy full-fledged full-term baby can be born at both 37.5 and 39.5 weeks. And no one, not a single person, calculator or apparatus is able to guess or find out how long it will take him to fully mature. That is why absolutely all calculation methods are conditional and inaccurate.

Shortening or lengthening the waiting period for crumbs is almost always a deviation from the norm. Exceptions:

• hereditary predisposition (deviation can be in any direction);
• multiple pregnancy (birth begins earlier).

preterm birth

Approximately 35% of babies are born prematurely. For some of them, early birth does not play any role. However, often children who have seen the world too early have severe health problems, need resuscitation and then special care.

There are very early births (22-27 weeks), early (28-33 weeks), actually premature (34-36 weeks). In Russia, a baby born after 22 weeks of gestation, weighing more than 500 g, with a body length of more than 25 cm and having one of the following signs is considered a live birth:

• breath;
• heartbeat;
• pulsation of the umbilical cord;
• muscle contractions.

Premature birth may be due to:

• stress
• stimulation of labor activity (sexual intercourse, climbing stairs, taking Oxytocin);
• pathology of the cervix, including cervical insufficiency;
• inflammatory process;
• high water;
• abortions and miscarriages in the past;
• and etc.

It happens that when trying to calculate the date of birth by menstruation, an error occurred. The baby, born at 36 weeks, actually grew and developed already at 38. The dominant role is played not by what date was originally set. The judgment about the urgency or premature delivery is based on the condition of the baby.

Postterm pregnancy

If the baby was not born on the 3rd day of the 41st week, then the pregnancy is considered postponed. This condition is more favorable than prematurity, because all organs and systems are already developed to the required state. However, the longer the child is in the uterus, the larger its size, the more traumatic the birth will be for the woman. In addition, prolonged stay of the fetus in the uterus helps to reduce the intensity of uteroplacental blood flow, causing oxygen starvation in the fetus.

The reasons for the late completion of the process of bearing a child may be:

• dysfunction of the placenta;
• endocrine pathology in the mother;
• large fruit;
• wrong psychological attitude, fear of childbirth.

Thus, there are many options for knowing when to expect a baby. You can calculate the date of birth by menstruation, the calculator will help you, you can use any other method described. The most important thing is to carefully monitor your body, avoid stress, regime failure, and carefully prepare for pregnancy. Then the process of expecting a child will be easy, and the birth will come on time.