How to correctly calculate the gestational age for the last menstruation. Exact gestational age - is it realistic to know
Our online calculator pregnancy will help you calculate your pregnancy by week. Pregnancy is an amazing period in the life of any woman, when inside appears and develops new life. This is happening at a fairly fast pace. In 9 months, the fetus goes through stages of development from a few small cells to an organized organism. With each week of pregnancy, the little one undergoes certain changes, improves existing systems, acquiring new qualities. Because future mother it is very interesting to find out during the whole interesting situation what new things happen to the baby, what he is like, what is on this stage can do. Description next.How to calculate the gestational age by week
For this, an interactive Pregnancy Calculator is intended, which allows you to calculate a woman’s pregnancy by weeks, find out in this way approximate date the birth of a child. The calculation is carried out from the first day of the last menstruation, although it is more correct to consider the term of conception from ovulation. Although the exact time of ovulation is not always known, the pregnancy calculator reflects the timing for the more common cycle of 28 days. With a long or short cycle, amendments are possible, although in practice it is customary to calculate the gestational age of a woman by menstruation. This Pregnancy Calendar is designed to calculate the due date key points fetal development and includes a birth calculator.What is gestational age and how is it calculated? It is customary to single out obstetric and embryonic terms, and many mothers simply get confused in these terms, and today we will try to figure it out.
The first thing we will start with is the obstetric term, because in fact, our gynecologist will make everything, all calculations based on obstetric period.
obstetric term
Obstetric term is calculated from the first day last menstrual period, so when you go to the gynecologist for the first time, clearly know the date of your last menstruation, this will make your life easier, and in the future all of your data will be entered in a special card, everything will be written there.
The obstetric period involves 280 days of pregnancy, well, these are averages, it is clear that each mother is an individual and this period may vary, but it is customary to consider 280 days.
According to the obstetric period, they issue directions for tests, a certificate of maternity leave and all other documents that you will need in the future, tighter exchange card, there all data will be put on the basis of the obstetric term.
And according to the obstetric term, the estimated date of birth is calculated, this is the PDR.
How to calculate the expected due date
The first day of the last menstruation, 3 months ago and 7 days are added, so you can calculate your gestational age and when your baby will be born.Embryonic term
It is calculated from the moment of conception and is usually shorter by 14-15 days of the obstetric period.
That is, in fact, we all know biology, menstruation has passed and a new cycle of egg formation has begun, and on day 14-15, on average, it matures and is ready for fertilization, this is called the day of ovulation.
In fact, it will be very difficult for us to determine and calculate the exact day of ovulation, of course there is different tests in a pharmacy, you can buy and know exactly when you ovulate,
but in principle it is very difficult to determine or calculate, because fertilization itself occurs on the day of ovulation, plus or minus 3-5 days.
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DATE OF PREGNANCY Calculator
For many women, the feeling of an impending or already begun pregnancy occurs before the test shows two strips - that is, even before the actual delay. Scientists cannot yet give an explanation for these true forebodings, however, the concept of Early Pregnancy Factor has already been introduced into the scientific lexicon, which describes chemical reactions maternal organism in response to an accomplished conception after only a few hours. Currently, there are already tests to detect the hormone in the female body. Early Factor, but due to the significantly expensive cost, these tests are not produced on an industrial scale.
On average, childbirth occurs 10 obstetric months (280 days) after pregnancy, when the baby is ready to be born. However, it should be noted that 280 days is the conditional number of days of bearing a child. All female organisms different, and all babies mature differently in their mother's tummy. Someone will need 280 days, and someone will be "already ready" in 240 days. Only 2% of newborns are born on a precisely calculated day. Most of the kids - two weeks earlier, or a few days later than the appointed time. The duration of pregnancy and childbirth is calculated based on the date of the beginning of the last menstruation.
If we take into account all the changes that happen to the baby almost every day on throughout pregnancy, and especially the first trimester, then in general these processes can be compared with the birth of a new universe in terms of importance and complexity, in depth. Every day of the little crumbs inside you is not just a step, it is a huge breakthrough, a breakthrough. The birth of a new life, despite the scale of accomplishments, does not require any external efforts for itself .. everything happens under the cloak of secrecy. After all, the fact that conception has occurred, and the woman herself finds out only after some time. Thanks to modern technology scientists managed to study a little great secret Birth is where EVERYTHING starts. Enter your data and scroll through the pages of the development calendar human life throughout pregnancy. Believe me, amazing discoveries are waiting for you!
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pregnancy calendars
Calculate your pregnancy calendar by week. Every week of your pregnancy from 1 to 40 weeks with details.
Pregnancy is an amazing and exciting time in a woman's life. In just 40 weeks, a whole organism is formed from one cell, capable of living in the environment. Man never again develops at such a rapid pace as in prenatal period. Every day the fetus changes appearance, there are new organs, new abilities. The appearance and well-being of a woman is also rapidly changing - last month her “ interesting position” was not noticeable to anyone, and today a pretty round tummy has already appeared. During the gestation of the fetus, you need to do a lot - you will have to go through more than one medical examination, pass several tests, review your menu and sleep patterns, change habits and update your wardrobe. It is better to prepare for all the changes in life in advance and especially so that you are aware of all the upcoming surprises, we have prepared detailed calendar weeks of pregnancy.
Where does the two-week confusion come from?
Doctors in women's consultations Traditionally, the gestational age is counted from the first day of the last menstruation, despite the fact that conception occurs, according to such calculations, only in the third week of pregnancy. Our interactive calendar built according to the same scheme - this is the so-called obstetric pregnancy calendar. There is another, much less frequently used, method for calculating the duration of pregnancy, when the day of conception is taken as the starting point. The resulting calendar, it would be correct to call the calendar of fetal development. Sometimes this method is reflected in the conclusions obstetric ultrasound, where it is possible to determine the life expectancy of the fetus with an accuracy of one day, especially in the first trimester. As a rule, the calendar of fetal development lags behind by about 2 weeks from obstetric calendar pregnancy.
It is most logical to describe the pregnancy by weeks - this way you will have a better idea of how your baby grows and what processes pregnancy causes in your own body. Studying the weekly pregnancy calendar, you will find timely advice on how to choose clothes for pregnant women, how to avoid toxicosis, how to eat right during pregnancy. Accordingly, each week the size of the fetus and its new skills are given - you will be surprised at how much it already has, when even the tummy is not yet visible to others!
In order to automatically calculate the pregnancy calendar, you can use the calculator on the site. Just enter the date of the first day of your last period, and you will receive a calendar of your own pregnancy by weeks. Perhaps it should be interesting for a pregnant woman to find out every week about how her baby's life is going, but you should not take the given terms literally. Keep in mind that the duration of pregnancy, as well as the rate of fetal development, is always individual and may differ slightly from the data provided by the interactive pregnancy calendar. The following pattern is characteristic - the longer the menstrual cycle, the longer the pregnancy lasts.
Questions for the article
Gram? Weight before pregnancy 80 kg, now 82.700. And seven weeks ago was ...
They said. And now I wonder))) what? ...
Estimated date was 04.07.17. But I still haven't given birth and nothing...
Cough, no fever. I am treated with chamomile, milk with honey, my nose is nothing ...
4 times a day. And at 10 pm I can eat. This is fine? I have 10...
Obstetric week, did in Moscow, they appointed a divigel and ...
fetus. This is fine. Sometimes there are imperceptible shocks. I have...
I did 3 tests, all 3 showed a weak second strip, the next ...
Indication 100102 .... this is normal, I'm very worried, tell me ...
Date of conception - 03/15/2017. HCG 04/06/2017 - 6145.2 mIU / ml. At the same time, less than 48 ...
Free, resultant 2.0 ng / ml - is this pregnancy ??? ...
That 6 weeks but shows like more. The ultrasound showed 4 weeks. Maybe...
1 day of delay the day before the start of menstruation, I watched the test showed ...
ml. Ultrasound on 01/11/2017 did not show anything. Please say this...
Doctors and ultrasound everything was fine, but for the last three days I started to get sick ...
I took Belara. On cancellation, menstruation came in the first cycle (33 days ...
Could this affect the baby? Can my gynecologist prescribe...
11/30/16 on hcg - result 1062.2. What does it mean? ...
Placental abruption 20mm by 4mm. The doctor said nothing, it will grow. But ...
2x five days)? 14 DPP - 1290 IU/L, 19 DPP - 6149 IU/L? Only on Uzi...
Pain began in the region of the pubic bone when walking and when ...
The second one is bright. And in the evening, spotting spotting a little ...
September, in October they are not) What is my week? How to calculate? ...
A week. Last menstruation 09/12/16 cycle 30 days. Gynecologist says...
The last menstruation was 04/27-05/04. May 5th was protected sex....
I read you in an article that it could be a fetus with Down syndrome ....
Syphilis, passed recently by her husband: anti-Treponema pallidum Ig M negative,...
The condom broke, is there a chance of pregnancy? ...
Change KP.) (Reference values 1.1-positive. What does this mean? ...
Be monthly. I did tests 28, 30 and so on. All are negative. By 8...
Weeks found at home there is a cat and he is constantly at home on the street ...
Sometimes a little 3-4 times a day is it normal pregnancy 16 weeks?...
Menstruation was noted not expressed pain in the lower abdomen, now ...
My throat hurt, then my nose stuffed up, not big snot, isn't it dangerous ...
1.00-5.00 and immature granulocytes 0.3% ref. interval 0.0-0.2. What is...
Vozmojno chto ya beremenna?i esli da ,to kakoy srok?pojalusta otvette esli mojno?...
Menstruation 07/19/20015. Thank you!...
Detachment of the placenta. If I understand correctly, the embryo does not receive enough ...
The previous children also had a tone and the doctor constantly scares me ....
(there is no year 16) PERSONAL PREGNANCY CALENDAR FOR ...
Weeks! a slight runny nose, tickle in the throat and weakness! isn't it like...
Lower abdomen as during PMS, spotting no, is it dangerous...
11/28/15 hCG showed 11564, which corresponds to 4 weeks of pregnancy, ...
At 6-7 weeks there was a threat of miscarriage, with a second pregnancy it can ...
Years, the cycle was approximately 34-35 days, but not exactly. pregnancy on...
The test showed that she was pregnant. but I don't remember the last date...
Keep in mind that, according to the calculations, I had to gain at least 5 kg ...
Regular. Now the delay is 7 days. Tests neg. On cycle day 16...
Accounting for pregnancy with a weight of 76.4 kg (term 5-6 weeks). Then I suddenly...
Menya.vozmojno beremennost v etom mesyace?i chto mojno zdelat zaranee chtob eto ne sluchilos?...
The beginning of menstruation on 09/02/15, in fact, conception occurred from 3 to 5 ...
Came with a delay of 2-3 days, the end in my 7.05 or 8.05. Sexual intercourse in...
The fact that the gynecologist did not listen to me carefully. The fact is that...
The anterior wall of the uterus. progesterone and papaverine were injected. everything ...
Praise and accept the likeness of the world? The date of the remaining months is 01.07.12....
Evenings before going to bed, not knowing that she is pregnant (for a period of 3-4 weeks) ....
pregnancy calculators
The calculator calculates your pregnancy based on your last period. The gestational age is obtained in "obstetric" weeks.
As a rule, every pregnant woman has her own calendar, where she enters all the necessary data, circles important dates taking notes. With its help, the gestational age is usually calculated.
Given the nine-month duration of this period, calculations on a piece of paper seem to be a very routine task. But modern women live at a great time - they are not at all obliged to keep such a calendar and do tedious arithmetic, unless, of course, they are so sentimental that they decide to keep their weekly notes as a memory of beautiful time gestation. You can safely entrust the program to take care of calculating the gestational age. Indeed, for those who prefer to spend their free hours on activities that are much more useful for the future baby and his mother, there are numerous virtual services like this one (we hint at our calculator).
What do you need to calculate the gestational age?
In order to calculate the gestational age right now, you only need to remember the date when the last menstruation began and enter it in the appropriate form fields. This number is the starting point of your pregnancy. It is about the so-called obstetric weeks”- all over the world it is customary to count pregnancy in this way, although fertilization occurs only in the middle of the cycle. This measure is necessary for the convenience of doctors, but often causes surprise and misunderstanding among patients.
Worth noting - ultrasound examination fetus, you will be faced with the fact that the gestational age known to you can be calculated differently - by weeks of fetal life, that is, from the day of conception. You may even find an entry on the ultrasound results sheet that lists both dates. In order not to be embarrassed by such contradictions, feel free to ask the doctors about what period pregnancy is coming speech, real or obstetric?
It is very important to emphasize that even if you know the exact date of conception of the baby, in order to calculate the gestational age using the calculator, you need to use the date the last menstruation began. If you find it difficult to remember, count 2 weeks ago - with a standard 28-day cycle, ovulation most often occurs on day 14.
I don't remember when I had my period. What to do?
Sometimes it happens that a woman does not know when she had her last period, for example, she does not remember, does not follow the regularity of the cycle, or has just stopped taking contraceptives. If you have no idea what your gestational age is, it can be calculated at. The data obtained from the early dates(up to 12 weeks), when the rate of development gestational sac are still very large and changes are noticeable literally every day. The size of the fetal egg alone, without taking into account the proportions of the fetus, will tell the doctor a lot. At later dates, errors of up to 2 weeks are possible.
Another very informative method that allows you to calculate the gestational age is biochemical - a study of a woman's blood for the content of hCG - chorionic gonadotropin person. This hormone is produced by the fetal egg and is present in the body only during pregnancy (by the way, it is on its determination in the urine that the well-known instant pregnancy test is based). Content and healthy pregnancy is clearly in line with the timing. It is worth noting that this is far from a routine method that requires a lot of time and money and is used mainly for medical reasons.
It is impossible not to mention that finding out the gestational age, calculating and assuming the probable age of the fetus is within the competence of the obstetrician when conducting a vaginal examination in the early stages. The main object of research in this case will be the uterus and palpation (manual) determination of its size. Of course, we are not talking about absolute accuracy, but the data obtained is quite enough for successful health monitoring. future mother and fetus.
Questions for the article
On the ultrasound on 06/30/2017, the doctor said nothing was visible, only there was a cyst...
I looked at the test, but I had negative result. but so...
The lower abdomen hurts periodically, it swells, it hurts the stomach, what can it be ...
Please, from what week can you feel the movement of the fetus? ...
The size of the fetal egg corresponds to 3-4 weeks, according to hCG on 2.02 4539, on 4.02...
Pregnancy ... but it's still too early to do the test and there is no delay, but I already ...
The result of hcg is 20.9 mlu/ml. what is my gestational age? last...
Please. The first day of the last menstruation is 04/20/2016. (conception after...
Accordingly, the period should be 8 weeks, but they put 4-5 on ultrasound ...
Discharge (brownish), what could that mean?...
Why should a pregnant woman and a doctor know what the gestational age is? Firstly, to determine the term of childbirth, secondly, to adequately monitor the development of the baby, correcting possible developmental delays in time, and thirdly, to determine the term for maternity leave.
I want to make a reservation right away that they distinguish between obstetric and true terms of pregnancy. Obstetricians begin to count the gestational age from 1 day of the last menstruation. This is quite justified, because from this moment the egg begins to mature, which the sperm will later fertilize, the zygote is formed and implanted in the uterus, the fetal egg begins to develop with the embryo, and then the fetus (after 12 weeks of pregnancy). The duration of pregnancy from the first day of the last menstruation to delivery is about 10 lunar months or 280 days or 40 weeks. However, each fruit has its own period prenatal development- from 37 to 42 weeks. It depends on many factors, but primarily due to genetics. It is necessary to ask at what gestational age the patient herself, the father of the child, was born, until what period the maternal relatives carried the pregnancy.
The true gestational age is two weeks behind the obstetric one - it is counted from the day of ovulation and conception. Thus, to determine the obstetric gestational age, two weeks must be added to the true one.
How to find out the gestational age by ovulation and the date of conception
Ovulation is the very period of the menstrual cycle when the conception of a child can occur. During ovulation, a woman's ovary fallopian tube a mature egg comes out and “waits” for spermatozoa there. Unprotected intercourse at such a time in more or less healthy woman and men are more likely to lead to pregnancy. According to the date of ovulation, the gestational age is determined.
A woman ovulates around the middle of her menstrual cycle (but not every month). If your menstrual cycle is 28 days, then ovulation will occur somewhere on the 14th day, with a 35-day menstrual cycle - on the 17-18th day of the cycle. Exact term pregnancy should be counted starting from the day of ovulation.
Ovulation can also be determined at home, using special tests sold in almost any pharmacy, or regularly measuring basal body temperature(temperature in the rectum). For the entire first half of the cycle, it will stay at about the same level - below 37 degrees. The day before ovulation will decrease slightly. And on the day of ovulation and on all subsequent days, you will stay at the level of 37-37.2 degrees. Thus, you can calculate the gestational age () if it began on the menstrual cycle when you determined ovulation.
There are women who can determine their ovulation without any tests and temperature measurements, just by subjective feelings- pain in the lower abdomen, increased libido, increased amount of vaginal discharge. So sensitive women it is easy to determine the gestational age yourself.
Most exact way determining the gestational age by the date of ovulation is an ultrasound. This is the only way to accurately see ovulation. Only now it is problematic for a week, or even longer, to go for an ultrasound scan every day. Yes, and materially such "pleasure" will not be available to every woman. Trying to determine your ovulation only so that later you can accurately calculate the gestational age is inappropriate. There are more simple ways calculating the gestational age already, in fact, after the onset of an interesting situation.
From the first date of the last menstruation count the number of days (weeks) at the time of examination of the pregnant woman. To determine the day of birth, 280 days (10 lunar months) are added to the first day of the last menstruation or the Negele formula is used: 3 months are subtracted from the date of the start of the last menstruation and 7 days are added. Similar Method cannot be used in women with irregular menstrual cycles.
Determining the gestational age by gynecological examination.
If you came for an examination to a gynecologist in the first weeks of pregnancy (at 3-4 weeks), then it will not be difficult for the doctor to accurately determine the gestational age. IN this case produced based on the size of the uterus. For example, at 4 weeks pregnant, the size of the uterus can be compared to chicken egg, at 8 weeks - with a goose egg. An experienced gynecologist is able to determine the gestational age by vaginal examination with an accuracy of one day. Pregnancy beyond 8-12 weeks is difficult to pinpoint just based on the size of the uterus. Since starting from the second trimester of pregnancy in women who are at the same gestational age, the size of the uterus may differ.
Determining the gestational age by ultrasound.
Of course, here, as in the previous method, much depends on the qualifications of the doctor who interprets the results. Ultrasound data obtained before the 12th week of pregnancy are considered the most correct for determining the date of the expected birth. At this time, the determination of the gestational age is based on the measurement of the fetal egg, its average internal diameter.
In the second and third trimesters, the gestational age is determined based on the determination of such parameters as the circumference of the fetal head, the average diameter chest and fetal tummy, fetal tummy circumference. The most reliable is the information obtained by measuring the circumference of the baby's head.
However, in general it is believed that late dates pregnancy error in determining the term using ultrasound increases. This is understandable: after all, each child develops individually, and at the end of pregnancy, the size of the fetus, which the doctor focuses on in his calculations, can vary significantly depending on the characteristics of a particular child.
With all the variety of methods for determining the date of the upcoming birth, there is no one “perfectly accurate”, as we have already said. Therefore, we can say that more or less precise definition the term of the upcoming birth is possible if all the data obtained are not contradictory, but complement and reinforce each other.
Although even in this case, the date of delivery can be shifted by one to two weeks in one direction or another due to the fact that urgent delivery (that is, delivery on time) can occur between 38 and 42 weeks of pregnancy.
Determining the gestational age by the first movement.
Primiparous women begin to feel the first movements of the baby at a gestational age of 20 weeks. Multiparous a little earlier - at 18 weeks. Gynecologists recommend that a woman remember the date of the first movement and be sure to enter it in the dispensary card of a pregnant woman. When setting the term of pregnancy and childbirth, this is of great importance. For example, in order to determine the date of childbirth, it is necessary to add 20 weeks (or 4.5 months) to the date of the first movement, for multiparous women, it is necessary to add 18 weeks or 5 months.
But this method of determining the gestational age is not always correct. There are women who, even in their first pregnancy, feel the movements of the baby much earlier. due date at 20 weeks, at 17 weeks, or even earlier. Especially often such early movements are observed in thin women. There are women who feel the first movements 2 weeks later than the due date.
Doctors about such early movements and setting the gestational age on their basis, there is an opinion. Most experts believe that women do not feel the baby’s movements ahead of time, but the “work” of the intestines. After all, as you know, most pregnant women suffer from increased gas formation ...
Determination of gestational age by measuring the length of the uterus and fetus.
You can calculate the gestational age in a complicated way. Only a gynecologist can make such a calculation. You are unlikely to succeed on your own. So, in order to measure the length of the uterus, the woman lies down on the couch and straightens her legs. Must be emptied first bladder, otherwise there may be errors in the determination right time pregnancy. The length of the uterus is measured using a centimeter tape or pelvis. Usually the length of the uterus is equal to the number of weeks. For example, the length of the uterus is 36 cm, which means that the gestational age is also 36 weeks.
