The article describes all the available ways to independently determine the date of your upcoming birth.

The emotional coloring of the news about expecting a baby begins to gradually lose its brightness and intensity characteristic of the first days, and you return to a more or less normal state. The first thing that usually comes to mind is to find out when the baby will be born.

This completely natural desire is due to both practical goals and simple human curiosity:

  • For some, the month of the year is interesting to start shopping for appropriate clothes for the baby
  • for some it is important to choose a name for a child according to the laws of astrology or the church calendar
  • for some, the expected date is needed to plan a spouse's vacation

The reasons may be different, but information about when a woman should prepare for childbirth is of interest to many expectant mothers.

Towards the end of the third trimester, women usually begin to calculate the expected date in every possible way, checking it again and again, because they feel heaviness and fatigue, and they cannot wait to meet their baby as soon as possible.

How to correctly calculate the due date? Table

Almost every person knows that it takes nine months to bear a child. But how to count them correctly:

  • from what day - sexual intercourse, ovulation, conception, implantation, last menstruation?
  • Should we take calendar months or conventional months of 30 days, exactly how many days do they have?

When an expectant mother faces pregnancy for the first time, a period of nine months seems very uncertain, and in order to calculate the due date as close to reality as possible, you want specifics.

The generally accepted method for determining the expected date of birth (hereinafter referred to as EDA) for the purpose of monitoring fetal development and pregnancy in general is counting from the date of the start of the menstrual cycle.

PDR = date of menstruation + 280 days (or 40 weeks)

In this way, conditional boundaries of pregnancy are established, called obstetric period, which becomes a guide for doctors and expectant mothers to monitor the progress of the baby’s development. When a woman is asked how far along she is, the pregnant woman will name the obstetric week of pregnancy.

In fact, true pregnancy occurred after the date of the last menstruation by approximately two weeks, and accordingly it lasts less than the obstetric period.

Why does the medical community resort to such a strange method of counting pregnancy from the day when it is only in the plans of potential parents? To find the answer, let’s briefly consider what happens in a woman’s “pregnant” cycle and when:

  1. regardless of when intimacy took place, fertilization or conception will occur on the day of ovulation, and taking into account the vitality of sperm, the difference between these moments can reach up to 5 days
  2. Ovulation occurs on average 14-15 days before the end of the cycle (next menstruation), but it can occur earlier (16 days) and later (12-13 days)
  3. Conception does not guarantee pregnancy; for this, the fertilized egg must attach to the uterus, or be implanted, which on average takes 6-8 days, but can also vary over time

IMPORTANT: 80% of cases of conception end in unsuccessful implantation, that is, pregnancy does not occur, but the woman does not even know about it, since her periods come on time.

So, it is very difficult to establish the starting point of pregnancy, due to the fact that it depends on several individual factors:

  • cycle duration
  • ovulation day
  • duration of implantation

Even theoretically knowing exactly the date of pregnancy, this would not guarantee one hundred percent determination of the date of birth, since the onset of labor is also determined by many factors, including:

  • physiological readiness of the baby
  • nature of pregnancy
  • mother's age and health status
  • number of previous pregnancies

For these reasons, doctors do not aim to accurately calculate the true date of conception and implantation. In addition, most women remember when they had their last menstruation, but not many people know what ovulation is and when it occurs specifically for them.

Therefore, it is much easier to count from the beginning of the cycle. This makes several assumptions:

  • cycle duration 28 days
  • Ovulation occurs after 14 days (on the 15th day)
  • the timing of implantation falls within the normal range

If you fit into the specified parameters, you can safely look in the table below for the date of the expected meeting with your baby. Nobody guarantees the exact probability, but this is as close as possible.

  • in the column on the left you should find the month in which you last had your period (indicated in black with an asterisk)
  • then find in the line with this month the number (indicated in black) corresponding to the start date of the last menstruation
  • below it will be indicated the expected date of birth and month (indicated in crimson color)

Examples given in the table:

  1. in a woman with the first day of her last menstrual period on March 28, delivery is planned for January 2
  2. if the onset of menstruation occurred on August 11, replenishment should be expected on May 18

If your cycle is slightly different, the table will also be a good guide, but you need to be prepared for the fact that a difference of 1-2 weeks is considered normal. In other words, from the point of view of medical science, the ideal pregnancy is 40 obstetric weeks, but more often it falls in the range of 38-42 weeks.

IMPORTANT: According to the latest data, the range of variation between the duration of pregnancy is 37 days or 5 weeks. Previously, this figure was 4 weeks (=42-38).

How to calculate the due date based on ovulation?

There may be cases when a woman knows exactly the day on which she ovulated. This is usually typical for women who have been planning pregnancy for a long time.

For example, ovulation became known using:

  • Ultrasound, which the woman had several times during the cycle to monitor the maturation and release of the egg
  • an ovulation test that shows a positive result 24-36 hours before ovulation
  • basal temperature chart
  • your own obvious sensations thanks to long-term observations of your body

In these circumstances, I would like to know the MRP more accurately, especially if the cycle does not fit the ideal standards both in terms of total duration and the number of days in the second phase. The formula for calculating day “X” in this case looks like this:

EDA = ovulation date + 266 days (or 38 weeks)

This period is called embryonic. If you compare these numbers with the traditional formula described above, you get a difference of 14 days (= 280-266). Namely, on days 14-15 of the cycle, ovulation occurs in an average cycle of 28 days.

Recent research from the US National Institutes of Health has concluded that pregnancy is often 268 days from ovulation (rather than the accepted 266), that is, 38 weeks and 2 days. The length of the gestational period also depends on how long it takes for the fetus to implant into the uterus. This point in the study was recorded on the first day of hCG growth.

IMPORTANT: It has also been found that the length of pregnancy is affected by the age of the mother and her birth weight. The older the woman and the higher her birth weight, the longer the gestation period will be.

How to calculate the due date based on the date of conception?

Conception or fertilization occurs when the sperm and the egg meet. Due to the fact that the egg leaves the follicle once a month (normally), which is called ovulation, and retains the ability to create a new life for only 24-36 hours, the meeting with the sperm and conception usually occurs on the day of ovulation or the next day.

Thus, the date of conception and the date of ovulation often coincide or differ by only 1 day. In this regard, the principle of calculating the PDR based on the date of conception is similar to the method based on the date of ovulation described above.

IMPORTANT: You should distinguish between the day of sexual intercourse and the day of conception. The difference between them can reach up to 5-7 days, depending on the life expectancy of the sperm of a particular man.

How to calculate the due date accurately based on menstruation?

The estimated date of birth, which the gynecologist will announce to the woman, as mentioned above, is based on data about the last menstruation. In this case, the day the cycle begins is important, that is, the date on which the last menstruation began; the duration and end date do not play a role.

In order not to count 280 days from this date, there is a simpler way (Naegele formula):

PDR = date of menstruation - 3 months + 7 days + 1 year

Example #1:

  • last menstruation was from June 13 to June 19, 2015
  • on the expected start date of the next cycle, April 10, menstruation did not start, and the pregnancy test was positive
  • you should remember the date June 13 (the beginning of the last menstruation), the pregnant woman will be asked this more than once
  • going back 3 months, we get March 13, 2015
  • add 7 days, we get March 20, 2015
  • we add a year, we get March 20, 2016 - this is the PDR

IMPORTANT: In the formula, the three months subtracted are equivalent to 92 days, so if the sum of the days in the months preceding the month of the last menstruation is 89, 90 or 91 days, you should add not seven, but 4, 5 or 6 days, respectively.

Example #2:

  • start date of last menstruation – December 15, 2015
  • subtract three months, we get September 15, 2015
  • sum of days of deducted months: November (30) + October (31) + September (30) =91
  • therefore, we add 6 days, we get September 21
  • add a year, PDR – September 21, 2016

Example #3:

  • date of menstruation – May 2, 2015
  • minus three months – February 2
  • sum of days in April, March and February (not leap year) – 89
  • so we add 4 days to the result
  • as a result, PDR - February 6, 2016

How to calculate the due date with an irregular cycle?

The calculation of the date of birth used in medical practice is based on the assumption that a woman has a standard cycle with a duration of 28 days, in which ovulation occurs on days 14-15.

Let's imagine the situation:

  • the date of a woman’s last menstruation is September 12, the maximum period for menstruation is June 19 (September 12 +280 days)
  • Day X comes, labor does not begin, the woman begins to worry, and the gynecologist insists on inducing labor, threatening the aging of the placenta
  • and only in rare cases will the doctor ask about the length of her menstrual cycle
  • Meanwhile, the expectant mother’s cycle is 40 days, which means that the due date, for objective reasons, shifts by at least 12 days
  • Ovulation most likely occurred not on the 14th day, but on the 26th day (=40-14)

IMPORTANT: Usually the duration of the second phase of the cycle is stable and is 14 days, that is, ovulation occurs 14 days before the end of the cycle.

  • in other words, conception occurred 12 days later than in the standard cycle (=26-14)
  • accordingly, the woman is not yet “over-nursing”, the duration of her true pregnancy has not yet reached 266 days, there is no reason for concern

Thus, it is quite natural that labor has not yet occurred, and the explanation for this is logical: the woman experienced late ovulation.

If you are the owner of a non-standard or irregular cycle (more or less than 28 days), it is better to focus on the date of ovulation and count from it (add 266 (268) days to the date of ovulation). If your ovulation date is unknown, you should:

  • find the difference between the number of days in your cycle and the standard
  • if the cycle is more than 28 days, add the difference to the maximum allowance calculated from menstruation
  • if the cycle is less than 28 days, subtract the difference from the MRP calculated by menstruation

In the example above:

  • the difference is 12 days =40-28
  • cycle more than 28 days
  • therefore, the more likely due date is July 01 (= June 19+12 days)

How to correctly calculate the due date using the first ultrasound?

To obtain more accurate results, ultrasound should be performed in the first trimester. If you go too early, at 4-5 weeks, that is, immediately after the delay, there is no guarantee that the doctor will even see the fertilized egg. Therefore, if there is no threat of ectopic pregnancy, you can sign up for an ultrasound after 6-7 weeks, and preferably in the period from 10 to 14 weeks.

Using an ultrasound, the doctor will assess the coccygeal-parietal size of the fetus, which can be used to determine the gestational age.

For example, if the fetal CTE is 44 mm, the gestational age according to ultrasound is 11 weeks and 2 days (or 79 days).

The table indicates the obstetric period. Accordingly, there are 201 days left (=280-79) or 28 weeks and 5 days until the birth.

In the 2nd and 3rd trimester, the accuracy of the correspondence of fetal parameters to the gestational age is significantly reduced, since the unborn baby begins to gain weight, grow and develop according to individual and genetic characteristics, which cannot be adjusted to any table.

How to calculate the due date after IVF?

  • Regardless of how conception occurred: naturally or in a laboratory setting, the gynecologist will still focus on PDR based on the date of the last menstruation
  • However, it is possible to calculate the embryonic period. The day of ovulation is taken to be the day of puncture, when follicular fluid with eggs was taken from the woman. You can add 266 days to this date and get a traffic permit
  • The same result can be obtained by adding 14 days to the puncture date, that is, conditionally determining the date of the last menstruation from which the obstetric period will be calculated, and counting 40 weeks (280 days)

How to calculate the due date based on the first fetal movement?

Fetal movement, although quite specific and real, is a subjective factor for determining the date of birth.

The fact is that it is very difficult to determine when the expectant mother clearly experienced the presence of a little man inside by his kicks and movements. First-time mothers notice this later than more experienced mothers, often confuse it with processes occurring in the intestines, and invent something that they cannot yet feel.

However, as a guideline, this method can be taken into account. To do this:

  • 20-22 weeks are added to the period when a primiparous woman first felt movement
  • 24 weeks are added to the date of the first tremors felt by a multiparous woman

The different periods are explained by the fact that the former feel movements only at 18-20 weeks, and the latter - from 16 weeks.

But this method can only roughly estimate the period of labor. At what point a woman detects the first movement depends on the structural features of the uterus, on the method of attachment of the fetus to the wall of the uterus, on the woman’s sensitivity and many other factors.

How to correctly calculate the date of the second birth?

There is an observation that each subsequent pregnancy is shorter and easier than the previous one. This is not always the case and depends on individual characteristics. But often the second birth occurs earlier, at 38 weeks, while the first - on average at 39-40 weeks. Otherwise, calculating the maximum age limit is similar to the principle of determining the date of the first birth.

  • It is known that the main reference point for calculating the PDR is the last menstruation, but there are frequent cases when a woman becomes pregnant again with a cycle that has not yet resumed after the first birth
  • What to do in this case? A woman does not know the date of her last period simply because she has not yet had one after her first pregnancy.
  • In such circumstances, the deadline is usually determined by the results of the ultrasound. This is the single most accurate way to determine the gestational age and calculate the due date. But it must be done no later than the 1st trimester

How to determine the exact date of birth yourself: tips and reviews

  1. If the menstrual cycle is 28-30 days, then the date of birth calculated in the antenatal clinic (for menstruation) will be closest to the truth
  2. If the cycle differs significantly in duration from the standard or fluctuates from time to time by more than 3-4 days, inform the gynecologist about this when registering
  3. In this case, keep in mind that labor may begin earlier or later than the ERP by the number of days by which your cycle is shorter or longer than the standard 28-day cycle
  4. You shouldn’t get too hung up on calculating the due date; the percentage of accurate hits is still not high
  5. Prepare mentally in advance that childbirth may occur earlier or later than the due date
  6. If the first birth occurred exactly in the PDR, this does not mean that the same will be the case with the second
  7. Remember that PDR is primarily needed for medical purposes: identifying significant deviations in fetal development depending on the duration of pregnancy, assessing the maturity of the placenta and monitoring other vital signs in order to timely hospitalize the woman and stimulate delivery if necessary

Video: How to determine the due date?

Gestational age- one of the main components that a gynecologist needs to know about for proper management of pregnancy. After all, on the basis of this, the doctor will prescribe the necessary examinations, tests, routine ultrasounds, monitor intrauterine growth and development of the fetus, and identify possible violations during the course of the pregnancy. In addition, determining the due date allows you to fairly accurately calculate the date of birth and the date of maternity leave. It is necessary for the woman herself to know the duration of her pregnancy in order to mentally prepare for childbirth, have time to prepare a room or corner for the unborn baby, and purchase all the necessary accessories and clothes for him.

In this article we will look at how to determine the duration of pregnancy.

Calculate by monthly

For a woman who comes to register at the antenatal clinic, the gynecologist first of all asks a question about when her last period began. It is from this date that he begins to keep a record, despite the fact that fertilization has not yet occurred. It is known that fertilization of the egg occurs on the day of ovulation, which occurs in the middle of the menstrual cycle. This method of determining the gestational age is called “obstetric”.

An online calculator will help determine the period:

How to determine the gestational age by the date of conception

It is known that conception occurs only during ovulation within 24 hours after the egg leaves the follicle. And the viability of sperm in the female genital tract is up to 3 days. It turns out that the date of sexual intercourse does not always coincide with the date of conception.

Ovulation occurs in the middle of the menstrual cycle. A woman who monitors her menstrual cycle can quite accurately calculate the onset of ovulation. In addition, many at this time develop characteristic symptoms: aching pain in the lower abdomen, breast swelling, irritability, copious vaginal discharge, increased libido.

It is worth noting that only those women who have a regular menstrual cycle can determine the gestational age by the date of conception.

Online calculator:

(calculation will take a few seconds)

How to calculate using ultrasound

It is possible to find out the gestational age using the results of an ultrasound examination (ultrasound). It is determined according to the size of the fetus. The first ultrasound of the expectant mother is performed at 12-14 weeks, but it is still impossible to accurately determine the period, since the development of the fetus occurs individually in each woman. It is possible to find out the age of the fetus by ultrasound with an accuracy of one day only in the first weeks after conception.

Determination during examination by a gynecologist

A gynecologist can determine a woman's gestational age by the size of her uterus during a gynecological examination. At 5-6 weeks, the size of the uterus can be compared to a chicken egg, at 8 weeks - to a goose egg. Later, it will be more difficult to determine how many weeks a woman has based on the size of her uterus.

Find out the due date by the first fetal movement

In the first pregnancy, a woman begins to feel fetal movements at 20 weeks, in the second - at 18 weeks. But this method does not always allow one to determine the period, since some expectant mothers may feel the first movements of the fetus earlier or later than the indicated weeks - some, due to the structural features of the body, cannot feel the movements of the fetus, others confuse the work of the intestines (increased gas formation) with movements.

Determine by hCG

Human chorionic gonadotropin (hCG)- one of the most important indicators indicating the onset of pregnancy and its normal development. The hormone begins to be produced in the female body after implantation of the embryo into the wall of the uterus. The level of hCG in the blood allows you to find out the approximate age of the fetus. With multiple pregnancy, the level of the hormone in the blood increases in proportion to the number of fetuses.

Week of pregnancy HCG level, honey/ml
1 - 2 25 - 156
2 - 3 101 - 4870
3 - 4 1110 - 31500
4 - 5 2560 - 82300
5 - 6 23100 - 151000
6 - 7 27300 - 233000
7 - 11 20900 - 291000
11 - 16 6140 - 103000
16 - 24 4720 - 80100
21 - 39 2700 - 78100
Views: 106551 .

Menstruation is delayed, and the two treasured lines are appearing more and more clearly in the tests? It’s still too early to go to the gynecologist, but you really want to find out when the baby who seems to have already settled in your tummy will be born? In this case, use our service to calculate your due date.

Calculate due date online

There are several methods for calculating the expected date of birth. All of them are based on the fact that a normal pregnancy lasts on average about forty weeks, counting from the beginning of the last menstrual bleeding. The expected date of birth will fall on the day that occurs 280 days or 40 weeks after the last menstruation began.

Calculating your due date using our service is very easy, convenient and fast - it only takes a few minutes or even seconds. To do this, you need to fill in the calculator windows with the numbers corresponding to the date of the first day of your last menstruation in the following format: day, month, year.

In just a moment, the calculator will calculate and display the result on the monitor.

This service works on the principle of calculating the duration of pregnancy, which in most cases lasts for 40 obstetric weeks or 280 calendar days. You can calculate your due date yourself by adding the required number of days/weeks to the day your last period started. But with the help of this convenient calculator, calculations are made easier, faster and without errors. However, you should understand that this is only an approximate, estimated date when you can expect to give birth. The length of pregnancy is influenced by a large number of factors, so it can last for different periods of time in different women.

Calculate due date based on date of conception

If you reliably know the day when fertilization occurred, then calculating the date of birth based on the date of conception will be even more reliable. To find out when the baby will be born, you need to add 280 days to the day on which the cherished sexual intercourse took place.

It should be understood that the date of sexual intercourse (even if you are almost one hundred percent sure of its authenticity and even if this month you had only a single case of sexual intercourse) is not always the date of conception of the child. The thing is that ovulation (the release of an egg ready for fertilization) can occur a day or two or even more after sex, but sperm that entered the vagina earlier can wait until this moment to merge with the egg and form a new life. Thus, the calculations may be off by several days. But still, the date of conception can be determined approximately.

You can also calculate the expected date of birth based on the day of ovulation. If you keep an appropriate schedule, the calculations will be quite accurate. But you can roughly calculate that very day, even without knowing the exact date of ovulation. It is believed that the egg matures approximately in the middle of the cycle. With a 28-day menstrual cycle, this moment occurs on days 12-15. By adding 280 days to the day of expected ovulation, you can calculate the date of birth.

Well, having received the result, proceed to pleasant chores and do not forget to visit the antenatal clinic on time, where you will be monitored for the next nine months.

See also:

Express tour: pregnancy week by week

Pregnancy women lasts 280 days or 40 weeks, which is 9 months. This difficult path to meeting mother and baby is usually divided into trimesters, each week which has its own characteristics and characteristics. Each trimester consists of three months.

First trimester: weeks 1-13

At the “start” after conception, an embryo is formed, but the signs are poorly felt by the mother. Details:

  • 1 week— for pregnancy to occur, it is necessary to attach an egg traveling through the tubes to the wall of the uterus. The expectant mother feels the world more deeply and becomes more thoughtful. Many women at this stage feel symptoms like before menstruation - pulling in the lower back, aching in the stomach. To determine the length of pregnancy in weeks and calculate the date of delivery based on the last menstrual days, use our pregnancy calculator. Try not to take pills and eat right;
  • 2 week- a follicle matures in the ovaries during ovulation, then it bursts, the egg comes out, the breasts become sensitive, irritability increases slightly, but libido also increases. No saunas or steam baths during this period! No heavy lifting! Only exercise, swimming, quitting smoking, orange juices and green vegetables rich in folic acid, which helps absorb iron! Taste habits change, you often want to go to the toilet, your blood pressure decreases;
  • 3 week- the embryo lives in the mother’s body, the egg is fertilized by a sperm, divides, and after 2.5 weeks reaches the uterus, which by the end of this period becomes loose. Nothing prevents the egg from reliably attaching to the mucous membrane. The metabolism changes, the mammary glands become coarser. You need to replace sweets with nuts, eat foods rich in calcium, proteins, folic acid, iron;
  • 4 week- the mother detects a delay in menstruation, nausea and malaise may appear. Hormones released during pregnancy can already be seen in the urine during laboratory analysis. The embryo develops internal organs, the mother needs vitamins;
  • 5 week- the uterus thickens, the baby looks like a tadpole, but its eyes and nostrils are already formed, it already has a heart, and the base of the skeleton is formed. The baby receives nutrition and oxygen from the mother's blood. A woman’s ovaries actively release progesterone, and the mother’s immunity decreases. In 7 days, the embryo grows to half a centimeter;
  • week 6— the amniotic sac is forming, protecting the embryo from any troubles, the nervous and circulatory systems are developing hourly. The processes of creation of the brain, liver, respiratory organs, and pancreas occur. The baby grows up to 1.3 cm;
  • week 7- the size of the embryo's head reaches 0.8 cm. The visual system is formed, the neural tubes thicken, the upper part of the intestine secretes the esophagus, stomach and pharynx, the bladder and rectum are visible under the lower part, and in male embryos - the prostate. A woman's facial skin may become oily during this period, like a teenager. Hormonal changes can cause itching. In case of any troubles, it is better to consult a doctor for advice;
  • 8 week- the nervous system receives maximum development, the medulla oblongata is ready for work, the spinal cord and brain are already fully formed, the eyes are still without eyelids, there is a nose, fingers and elbow joints appear on the arms. Mothers should protect themselves from infections;
  • Week 9- the third month begins, the face takes on human features, eyelids form, a sucking reflex appears, the circulatory system circulates inside the tiny organism, the heart acquires three chambers, the bronchi branch. Mom's breasts increase so much that the next bra number is required. The uterus enlarges, the ligaments stretch, pulling sensations in the lower abdomen are normal for this period;
  • 10 week— A 5-centimeter embryo is already considered a fetus; an ultrasound can determine its gender. His nervous system is divided into central and peripheral, the hemispheres of the brain become more independent. The enlarged uterus can be felt even with your hands, you constantly want to go to the toilet;
  • 11 week- the baby’s body gradually straightens, reaching 5.9 cm, the legs begin to actively catch up with the arms, irises form near the eyes, and lymphocytes appear. The mother's kidneys experience a double load, removing waste products for two;
  • 12 week- A 50-gram fetus has grown to more than 7 centimeters, the chest moves noticeably when breathing, the heart beats more than 150 beats per minute, milk teeth, vocal cords, and diaphragm are forming. The mother needs to get enough sleep, exercise, and remain calm;
  • Week 13— the placenta has reached 16 mm, becoming reliable protection for the baby. From this moment on, the body will even tolerate taking antibiotics if necessary. Bones and ribs need calcium. Without subcutaneous fat, the skin appears wrinkled. Mom may become constipated, her blood pressure may drop, and her kidneys may be bothered. It is important to eat right in order to gain no more than 11 kg during the entire pregnancy, and for a multiple pregnancy - no more than 17 kg;

Second trimester: 14-27 weeks

This is a gently flowing period of bearing a baby, during which the mother’s body is completely ready to work for two, despite the weight gain, rounding of shape, and the appearance of a belly. The embryo's internal organs and systems are fully formed, the child moves his limbs, sucks his finger, and the feeling of his movements gives the mother endless delight. More details:

  • Week 14— the baby maintains the chemical composition of the amniotic fluid by secreting urine into it up to several times a day. The ovaries in girls and the prostate in boys are improving. Lack of vitamins affects the mother’s well-being. She has the feeling that there is not enough air. It is worth eating less potatoes and legumes. You may be allergic to strawberries, peaches, and oranges;
  • Week 15- the baby’s heart distills about 23 liters of blood, convolutions form in the brain, bone marrow develops, the intestines form original feces, and the amount of amniotic fluid increases. You can talk to your baby! The height of the uterus reaches 14 cm. The woman begins to blossom;
  • Week 16— the date the baby moves helps to more accurately determine the date of delivery; he actively moves every 10 minutes. He opens his eyes for the first time. Fetal movement may appear by the 20th week. Exercise and the right menu improve the mother’s condition;
  • Week 17— the weight of the fetus exceeds 100 g, and the height reaches 12 cm. He and the mother require calcium and healthy food, since the body type is being determined. A woman feels pressure in her stomach and liver. You have to eat many times a day in small portions so that your stomach has time to cope. Sometimes leg cramps appear due to a lack of B vitamins, magnesium, calcium;
  • Week 18- the height of a small child is 13 cm, weight - 170 g, head diameter - almost 4 cm, fingers become proportional, foot length reaches 2.5 cm. Mothers rejoice, feeling his movements. At this time, there is a high probability of determining the baby’s gender using an ultrasound. The ideal weekly weight gain for a mother is 500 g. To reduce swelling, you need to consume less salt;
  • Week 19- the child reacts to screams, the volume of the voice, turns his head towards the sound. Listen to pleasant music, do not quarrel with your family. A pattern is formed on children's palms. The kicks in the tummy become more distinct. Women do not always distinguish the movement of the fetus from the processes that occur in the intestines;
  • Week 20- the endocrine system is formed, parts of the brain are improving, the baby can swallow, has good hearing, his weight is about 290 g, his height is about 24 cm. Mommy’s waist disappears from the rounding of the tummy, the first stretch marks appear, a comfortable bra is required;
  • 21 weeks- if a baby is suddenly born after this period, his ability to survive increases significantly. Systems and organs are formed, the stomach and chest, the head grow, subcutaneous fat is formed, receptors on the tongue distinguish taste, the first leukocytes appear in his body. Requires a lot of protein and 4 times more carbohydrates;
  • Week 22- the brain weighs 100 g, the height of the fetus is 28 cm, weight is about 430 g, the mass of the heart increases, ligaments and vertebrae are clearly visible. It is necessary to count the baby's movements, since swelling can compress the blood vessels that carry nutrition to the placenta;
  • Week 23- alveoli are formed, the respiratory system develops. Mom needs to drink a lot of water, since plasma consists of it. The fuzz on the child’s head is noticeable during ultrasound examination; the muscles, spine, bones, and aorta are clearly visible;
  • Week 24— the baby’s skin gradually smoothes out, thanks to the appearance of subcutaneous fatty tissue. The baby feels the mother's emotions. The doctor listens to how the heart beats, whether the chest and tummy have grown, what is the diameter of the head;
  • Week 25— the child’s weight is 680 g, height is 34 cm. The bone marrow is connected to blood formation. In order for the alveoli to function, surfactant accumulates in the lungs. The fundus of the mother’s uterus has risen to 25 cm, her legs get tired more often, and lower back pain appears;
  • Week 26— the baby has grown to 35 cm, gained more than 770 g, smells, reacts faster to voices. The diameter of the head is now 65.1 mm, the stomach is 67.4 mm, the chest is 65.8 mm. By this time, the woman puts things aside and spares herself more;
  • Week 27- setting the speed of reactions and metabolic processes. The mother needs to gain strength for the upcoming third of gestation. The period is characterized by frequent shortness of breath due to a feeling of lack of air.

Third trimester: 28 weeks and until delivery

The most difficult stage for a mother is from 7 months before giving birth. It is accompanied by the active growth of the baby, preparing the child for independent existence. Details:

  • Week 28- the baby is exactly 7 months old, you can determine whether he will be right-handed or left-handed. To do this, the ultrasound shows which hand he most often reaches for his mouth. There is already enough surfactant in the lungs to prevent the alveoli from sticking together during the first breath;
  • Week 29— the baby’s height has reached 38 cm, weight is more than 1 kg. Only his belly and folds are lubricated. He becomes cramped inside his mother, and the blood fully protects him from infections, but venous and arterial blood still mix. The daily portion of urine excreted is 500 g. The mother is entitled to maternity leave at this time;
  • Week 30— the baby’s chest has grown to 77.4 mm, and the tummy has grown to 79.3 mm. The cerebral cortex is formed, the child begins to remember some sounds and sensations. Mom will have to visit the gynecologist weekly. Due to the increased pressure on the blood vessels during sleep, your arms go numb and your legs cramp. The ligaments become elastic, you can do light stretching exercises in the pelvic area;
  • 31 weeks— the child’s weekly weight gain is about 200 g. The child needs subcutaneous fat that retains heat. The pigment accumulates in the hair and iris of the eyes. Sometimes the uterus rehearses childbirth, and one-time contractions appear;
  • Week 32- the baby weighs 1700 g, body length - over 40 cm. If the placenta “gets old”, nutrition will be disrupted, and developmental abnormalities will appear. By this period, the first hair appears. The mother produces vasopressin and oxytocin;
  • Week 33- the child has to assume the fetal position because there is not enough space. The body reached 43 cm, the head - 8.2 cm, the tummy - 87.4 mm, the breast - 85 mm. The placenta copes with the function of protecting the baby from harmful factors and nourishes it through the blood;
  • 34 week— the baby weighs 2.1 kg. The placenta produces hormones that cause lactation. Its thickness is 3.39 cm. It is important not to overdo it with calcium intake in order to avoid birth injuries. It is necessary to continue to count the movements of the fetus - 4-6 movements are considered the norm;
  • — childbirth is possible this week, but much is determined by heredity. The head is 1/4 the length of the body, its diameter is 91 mm. The feet became more defined. The baby's genitals and reflexes are developed. The placenta dries out and supplies nutrition worse. The mother is focused on the upcoming meeting with the baby;
  • Week 39- the baby weighs 3.3 kg, height - 51.5 cm. Thanks to the fontanelles made of cartilage tissue, the bones of the skull remain pliable so that the child can pass through the birth canal. The baby will be able to distinguish objects at a distance of 30 cm from the eyes. The placenta ages and the fetus experiences a lack of oxygen. Mom prepares things for the maternity hospital and documents;
  • 40 week- the child patiently waited for this hour, gained more than 3.5 kg, grew to 53 cm. The mother becomes worried if labor does not occur. Before giving birth, you often want to go to the toilet, your lower back ache, your cervix gradually opens, and colostrum is released from your nipples.

If labor does not occur at 40 weeks, it doesn’t matter. The norm is resolution within 42 weeks. All you have to do is trust nature. Only 10% of women in labor reach the 42nd week. Dopplerography and ultrasound are performed to assess the condition of the baby and mother. The main thing is to remain calm so as not to harm the health of mother and child.

"cervix" in Latin means "cervix") or the cervical canal. The cervix is ​​4 cm long and the width of the cervical canal is a maximum of 4 mm. The shape of the canal resembles a spindle, that is, its widest part is in the center of the cervix, and the canal narrows upward and downward. This form ensures the preservation of the mucous plug, which is normally present in the cervical canal.

Description

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

Researchers from the Oregon Center for Genetics and Perinatal Medicine (USA) analyzed several thousand birth histories and came to the conclusion that in the vast majority of cases (95%) the date of birth does not coincide with the one they tried to determine in advance

How to determine the due date? Sometimes you want to know exactly when the baby will be born simply out of curiosity, and sometimes for some practical reasons: state exams at the institute, moving to a new apartment, and who knows what else. In a word, almost all mothers want to know more precisely when the baby will come into this world. However, it is not possible to calculate this date absolutely accurately, down to the day. And here's why.

Let's assume that the mother knows exactly when the fateful sexual contact took place, which gave birth to the baby, but sexual contact and the date of fertilization are far from the same thing. After all, it is known that sperm that enter the female genital tract retain the ability to fertilize an egg from several hours to several days.

If they try to determine the beginning of pregnancy by the date of ovulation, then everything is not so simple here either, because ovulation can occur between the eighth and sixteenth day of the cycle. And this depends on the duration of the cycle, and on many external reasons, such as fatigue, anxiety, colds.

We take into account that pregnancy can occur a couple of days after ovulation, when the egg and sperm are still viable and ready for conception, that is, right up to the eighteenth day of the menstrual cycle, and if we take into account the viability of individual sperm that have entered the female genital tract, we can safely add a couple more days. Thus, it turns out that pregnancy can quite realistically occur before the twentieth, or even the twenty-first day of the cycle.

And if the menstrual cycle is short, then everything becomes even more confusing. Suppose the menstrual cycle is 21 days, but the periods are long - lasting a week.

Then ovulation occurs almost immediately after menstruation, and even if unprotected sexual intercourse occurred during menstruation, then, given the ability of sperm to fertilize within several days, pregnancy is quite likely even after such sexual intercourse. A short cycle, ovulation on the eighth–ninth day, sperm viability - this means pregnancy even with sexual intercourse during menstruation.

So you can remember the date of sexual intercourse absolutely accurately, but it is not at all a fact that pregnancy occurred right then, and not slightly later.

What else can influence the date of birth, and at the same time complicate the calculations? Traditionally, a normal pregnancy is considered to last 40 weeks. But this is not always the case - the fact is that the pregnancy is considered full-term by the 38th week, therefore normal labor can begin at any time after this period.

One more point: if twins are to be born, that is, the pregnancy is considered multiple, then in the vast majority of cases labor begins a week or two earlier.

Don’t forget about a young mother: for example, a mother’s hypertension can delay the due date in the same way as diabetes. Any chronic and acute health conditions, emotional background, fatigue - absolutely everything can affect the timing of childbirth.

There are a lot of reasons that can affect the due date, let’s add here the practical impossibility of accurately determining the date of conception - so it turns out that the date of birth can be guessed or not, but it is practically impossible to calculate it with any certainty.

The main thing is to treat this with understanding - the baby will come into this world only when he is completely ready to face sunrises and sunsets, snow and rain, sun and rainbows.

However, be that as it may, the approximate date of birth can be determined (but only approximate!). It must be said that gynecologists suggest determining not the exact date of birth, since this is still very problematic, but the week when the birth should occur.

Let's ask the moon

A very popular miscalculation option is when ten lunar months (280 calendar days) are added to the beginning of the last menstruation - thus getting the expected day of birth. There is another option: from the beginning of the last menstruation, three months are counted and seven days are added (Nägel method) and the approximate due date is obtained.

Why are these calculation methods inaccurate? Yes, because the menstrual cycle is not always 28 days, it can be noticeably shorter or significantly longer, in addition, the menstrual cycle is not always regular - and then it is generally impossible to determine the date of ovulation.

But if the mother absolutely knows her cycle, which, besides everything else, is always stable, then you can try to calculate the date of the expected birth in one more way.

It is necessary to determine the day of conception, for which 14–16 days are subtracted from the first day of menstruation that never came. And if the day of conception is known, then, based on the duration of pregnancy of 10 lunar months, the day of birth can be determined. But everything, again, is very approximate.

Let's move!

You can try to determine when the baby will be born by noticing when he first began to move in mommy's tummy. The day of the first fetal movement is a very significant date.

If a young woman is going to become a mother for the first time, then twenty weeks should be added to the day when the baby first moved, and if the mother is not going to give birth to her first child, then twenty-two weeks should be added.

The fact is that the baby’s movements are perceived very subjectively: women who have already given birth can feel the baby’s movement much earlier, even before the eighteenth week of pregnancy, and a nulliparous mother can confuse the baby’s movements even with intestinal peristalsis - everything is extremely individual. This is where the inaccuracy of this method of determining the due date comes from.

Consult a consultation

“By first appearance at the antenatal clinic” is the name of the next method for determining the time of birth. The sooner a woman contacts an antenatal clinic about pregnancy, the more accurately the gestational age and, accordingly, the due date will be determined. It is generally accepted that the most accurate prognosis can be obtained if a woman consults a doctor before twelve weeks of pregnancy.

In addition, the doctor can determine the gestational age, respectively, and the date of birth, based on some completely objective indicators: the size of the uterus, the volume of the abdomen, the height of the uterine fundus, the length of the fetus and the size of the head. At four weeks of pregnancy, the size of the uterus is approximately the size of a chicken egg, at eight weeks it reaches the size of a goose egg, and at 12 weeks of pregnancy, the uterus is approximately equal in size to the head of a newborn.

The abdomen becomes noticeable (the so-called protrusion of the abdominal wall) at the end of the twentieth week of pregnancy (the end of the fifth obstetric month).

The gestational age can then be determined by how the upper edge of the uterus is positioned.

Ultrasound and due date

Ultrasound examination is one of the most modern and most reliable ways to determine when a baby will be born.

It’s interesting, but the most accurate way to determine the date of future birth is to use ultrasound data obtained up to three obstetric months (12 weeks). At this stage, the fetus develops approximately the same for everyone, and the gestational age can be determined after measuring the fertilized egg and its internal diameter.

Later, in the second and third trimesters, they try to determine the exact duration of pregnancy by studying ultrasound data on the circumference of the fetal head, the diameter of the baby’s chest and tummy. But the most reliable information is obtained after measuring the circumference of the baby’s head.

It would seem that the closer to the time, the more accurately you can determine the due date. But no! It is believed that in the later stages of pregnancy it is much easier to make a mistake during an ultrasound, and no wonder, because each child develops in its own way, and by the end of pregnancy, children are completely different: a healthy child can be born weighing 2.5 kg, or weighing 4 .5 kg. So it’s not for nothing that ultrasound data are the most accurate at the very beginning of pregnancy, when the cell has just begun to divide, and the individual characteristics of the baby are not yet particularly pronounced.

There is no reliable method

But no matter how hard a young mother tries to determine the time of birth and find the most reliable method, only one thing can be said with confidence - there is no completely reliable method for determining the time of birth.

It is possible to speak with any accuracy about the timing of birth only if the information obtained from all methods does not contradict each other, but only complements each other. Although no matter how accurately the timing is predicted, labor will still begin only when the baby decides that it is time for him to take a closer look around. The main thing is that the birth should be on time, that is, on time, and this is the period from the 38th to The 42nd week of pregnancy, and the exact day of birth can only be guessed by chance, and the day named by doctors is a very approximate date.

It is clear that the young mother is very worried, and if contractions do not start at the “calculated” time, this can cause severe stress.

But every pregnant woman should understand well that it is impossible to accurately determine the time of birth, that any doctor, based on the results of any research, can only give an approximate (so-called estimated) date, and the difference with the actual birth can reach up to two weeks (either one or two weeks). other side). So a young mother must trust herself, her feelings, listen to the child inside herself - he knows exactly when he should be born.