When you find out that you are pregnant, in addition to excitement in your head, many questions immediately arise: what is the pregnancy period, how to calculate it and when will that treasured day of meeting with the baby come? How can we calculate the duration of pregnancy, and which one is the most accurate, we will tell in our today's material.
To begin, let's define whatpregnancy does not lasttraditional9 calendar months, and 10 lunar months, and is about 280 days.
In order tocalculate the gestational ageDoctors take the starting pointthe first day of the last periodand not the day of conception, although at this moment the woman is not exactly pregnant. This is because the exact date of conception is very difficult to determine, and sometimes simply impossible, and when the last menstruation began, almost any woman can say.
Directlyfertilization processoccurs approximately two weeks after the onset of menstrual flow. And some research data, for exampleultrasound resultswill show alreadyreal term of fetal developmentwhich will be less obstetric for two weeks.
Without knowing this nuance, pregnant women often wonder why the doctor’s calculations about the duration of pregnancy and the ultrasound data do not match. In order not to worry once again, remember: the doctor considers pregnancy byobstetric terms, from the first day of the last menstruation, and ultrasound showsreal term from the day of conceptionindicating the exact age of the fetus. The discrepancy between these dates is usually about 2 weeks.
The doctor's notes after the examination are questionable? Feel free to clarify what kind of time it is talking about this time - real or obstetric.
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It is unlikely that many future moms canspecify the day on which the conception took placeBecause sometimes this fact remains a secret even for a pregnant woman, not to mention doctors. For you, the day of conception is not "a secret behind seven seals"Do you know this date exactly? Then, with the calculation of the duration of pregnancy, you will have no problems, and if you add 280 days of pregnancy to the conception date, you can find outapproximate delivery date.
If you do not belong to those lucky women who are confident in the date "X", calculateobstetric termpregnancy can be usingNegele formula. At the reception, the gynecologist will ask you the date of the first day of the last menstruation, take three months from her and add 7 days.
Tocorrectly calculate the timepregnancy byNegele formulaThe date of the beginning of the last menstruation needs to be known for sure; for this, doctors advise women to keep a special calendar, on which to mark the beginning of each menstruation.
The calculation by the formula is absolutely simple and you can make it yourself. Suppose you have the last critical days started on April 15th. Subtract three months from this date — it will turn out on January 15, and add 7 days. Estimated date of birth January 22.
If you measured yourselfbasal temperatureand you know for sureovulation day, the calculation of pregnancy can begin exactly from this day.In order to know the estimated time of birth to the date of ovulation, you can add 264 days. However, these data, doctors often do not take into account, and you can simply keep them for yourself.
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Most often, in order to establish the current duration of pregnancy is usedfetal ultrasound methodas it can be donemost accurately.
Up to 5-6 weeks, the embryo is still very small, so the duration of pregnancy on an ultrasound is determined by the size of the internal diameter of the ovum. At week 7-8, the embryo is already visualized and to determine its size, an indicator such asKopchikovo-parietal size.
Due to the fact thateighth week of pregnancyall healthy embryos develop in the same way, during this periodusing ultrasoundby fetus sizecanestablish the exact duration of pregnancy.
In the future, babies begin to develop individually: someone will be a little more, and someone, on the contrary, will be slightly less than the standard sizes defined by doctors. Most often, the deviations are minor - on average for a week, and do not pose any danger.
Due to individual developmental parametersstarting fromII termfor determining the age of the fetus instead of the coccyx-parietal sizeuse several parameters: head circumference, abdominal circumference, fronto-occipital size, length of the femur and humerus, bones of the leg and forearm.
Based on the data obtained by ultrasound, the doctor will tell you how long your pregnancy is in weeks.
Obstetrician-gynecologist, specialist of ultrasound diagnostics of the medical company Ilaya Alina Palamarchuktells:«Of all the research methods that give the maximum idea of the placenta, uterus, fetal development and other nuances, the most effective is ultrasound. In order for the doctor and future mom from the very beginning of pregnancy to know for sure if everything is in order with the child, the first ultrasound scan is recommended 10-14 days after the delay of menstruation. At this time, it is already possible to understand that pregnancy develops in the uterus, see the elements of the ovum, the embryo, its heart, and prevent problems that may hinder the development of the child in the future. ”
Determine pregnancy withtraditional examination on the gynecological chairin the first month of pregnancy is quite difficult, due to the fact that the uterus before the onset of menstruation is also prone to increase. Say about the alleged pregnancy based on data of a pelvic examination, it will be possible only afterat least three weeks after the delaymenses.
Based on the size of the uterusyou can set the duration of pregnancysecond trimester. During a visit to the antenatal clinic, the gynecologist will necessarily weigh the pregnant woman and measure her abdominal circumference with a centimeter. The obtained measurements are compared with the standards of fetal development, based on which, you can determine the duration of pregnancy, because every month the uterus increases by an average of 1 centimeter. For example, in the 20th week, the bottom of the uterus should be located two fingers below the navel, on the 24th, the uterus is felt at the navel level, and on the 28th, the bottom of the uterus is located 2 fingers above the navel. In addition to the diagnosis of pregnancy, measuring the length of the uterus helps gynecologists to verify the normal development of the fetus, in time to detect polyhydramnios, lack of water, or other pathologies.
Important nuance: this method of calculating pregnancy is difficult to rely on completely,because measurement results may be affected by inaccuracy of measurements or individual features of the future mom.
Vitaly Kuprienko, a gynecologist, tells:“Additional examinations and examinations during pregnancy may be needed if a doctor suspects the development of infectious diseases, the symptoms of which are unpleasant sensations in the genital tract, itching or rash on the genitals. You also need to see a doctor unplanned if you have bleeding or a small bleeding from the genital tract. ”
Read also: Abdominal growth rates in pregnant women
In female consultationsthe moment of the first stir of the babyThe gynecologists pay a lot of attention: they ask the future mom to remember and write down when she first felt these indescribable feelings, the data obtained necessarily fit into the registration card of a pregnant woman.
It is traditionally considered that if a woman wears a firstborn, then she can feel his first movements on20th week of pregnancy. Felt the first stirring in this period? You can add another 20 weeks,and get an estimated delivery date. If you are preparing to become a mother a second or more times, you can feel the movements of the baby earlier, already on18th week of pregnancy.
Although, according to the stories of future moms, sometimesthe timing of the real first movements of babies do not coincide with the established. It is also quite difficult for some women who have become pregnant for the first time to understand whether this baby really moves in the tummy, due to the fact that they have never experienced such sensations.
Our mother forumchankaOsyta tells:“I was really looking forward to the first movements, the doctor traditionally said that this would happen around the 20th week, but I definitely felt them already on the 22nd. As if the waves in the stomach, so interesting. But my girlfriend, we have almost the same time with her, I felt the first movements at the 16th week. I was so jealous of her and worried about everything, but is everything OK with my “putozhitel”? Why doesn't he move? Although, maybe he just moved, I just could not understand it. And then already when the baby began to seriously push, not to understand what he was there, it was simply impossible! ”
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Alreadyon term 4-5 weeksthat is, 2-3 weeks after the delay of menstruation,the baby's heart starts to beat. You can see the heartbeat on ultrasound, the presence of heart rate will help not only calculate the duration of pregnancy, but also to make sure that the baby is alive and developing.
Hearbaby's heartbeat through the outer wall of the uterusWith the help of a stethoscope, the doctor can later, approximately at the time of the first movements of the baby. Thus, if the gynecologist speaks at a reception that hears the heart of your baby, then the gestation period is from 16 to 20 weeks. The longer the gestation period, the better the baby’s heart rate should be heard.
Human chorionic gonadorpineIt begins to be actively produced in the female body upon the occurrence of pregnancy and the formation of the placenta, and can also help in calculating the duration of pregnancy.
During the first weeks of pregnancy, the content of hCG in the blood of a pregnant woman grows rapidly:
Its maximum level of hCG reaches at 9-12 weeks, in the second trimester its content decreases slightly, stabilizes at a low level, and then increases slightly.
However, due to possible errors, this analysis is rarely used to calculate the duration of pregnancy, it is mainly used for its early diagnosis.
We have given the basic methods of how to correctly calculate the duration of pregnancy. Some of them can be tried on their own, while others require medical intervention and some procedures.
As you can see, ways tocalculate the gestational ageenough. It is important for both the pregnant woman and the doctors to know this information in order to come for a certain period of time for tests, pass mandatory tests and undergo screening tests to identify possible fetal development disorders.
In addition, if you correctly calculate the duration of pregnancy, then with the definitionpreliminary date of deliveryyou also will not have problems, you will be able to go on maternity leave in time, relax and prepare everything you need to meet a long-awaited baby.