How to determine the duration of pregnancy
The exact period of pregnancy is important forof the planned caesarean section (to avoid premature surgery) if the pregnant woman is diabetic (complications can occur if the fetus is larger than the normal one). Determination of the gestational age allows you to timely diagnose abnormalities, violations of the development of the fetus (for example, Down's syndrome) and accurately determine the date of birth. When the doctor knows the time, with the help of ultrasound you can compare the generally accepted characteristics and the development of the fetus with a specific pregnancy. So, how correctly to determine the duration of pregnancy? It would seem that an independent definition of the term is a simple matter. The following calculation formula is generally accepted: on the first day of the last menstruation, 280 days (40 weeks, 9 calendar months or 10 obstetric) should be added. Basically, the definition of the approximate date of birth is simplified: from the first day of the last month, 3 months are counted back and 7 days are added to the received date. For example, the beginning of the last menstruation fell on December 15, then, counting 3 months ago (September 15) and adding 7 days, get the date of birth (September 22). But this formula does not always give an accurate result. Features of the body of a woman and a developing child can make significant adjustments. 280 days is the average duration of pregnancy, however in each specific case there may be fluctuations ranging from 38 to 42 weeks. The 2-week variation is normal. As a rule, girls are born a little earlier than boys, who, on the contrary, do not hurry to get acquainted with the world around them. Determining the gestational age by conception You can find out the gestation period by the date of conception or the day of ovulation. The chance to become pregnant in ovulation is very high. The main difficulty is that in the first days and sometimes weeks of pregnancy no reliable signs are shown. Although a number of signs are used to determine it, the exact date of fertilization is still suspected, since the signs themselves are mostly presumptive (especially in the early weeks). Conception of the child is the fusion of the sperm and the egg, which occurs within a day or two after ovulation. Some women can determine it by themselves for some symptoms, others for its detection get special tests, and others measure their basal temperature - the temperature in the rectum. The first half of the menstrual cycle is characterized by a temperature of not more than 37 ° C. The day before ovulation, the temperature will drop slightly, to then rise to 37-37.2 ° C. Thanks to this, it is possible to calculate the exact day of conception, provided that it occurred precisely during the measurement period. For women who feel ovulation and know the day of conception, it is the easiest to determine the date of pregnancy on their own. But even with the exact calculation of the day of conception (if the sexual act was once) for a number of reasons gynecologists put a period longer for 2 weeks. Women think this is a sign of a large child. But in the early weeks, the size of the embryos is practically the same. Gynecologists simply state the period of gestation (gestation). It calculates the date of future birth. Therefore, knowing the time of the day of conception is not interesting to the doctor, but to the woman herself. By the way, some women keep their calendar. Then it will be interesting to compare the calendar and medical term, to determine which was more accurate. 
How to determine the duration of pregnancy for the first movement of the child
An important parameter of the course of pregnancyis the first stirring of the unborn child. After all, doctors, as is known, take into account the future term of childbirth, depending on the results of ultrasound in the first trimester and the date of the first stirring of the child. Women who give birth for the first time, feel such perturbations in the 20 th week, and a few months earlier - on the 18th week. But often primiparous women and re-borne children feel the movements of the child from 15-16 weeks, although some future mothers may not feel fetal movements until 21-22 weeks. This is due to the activity of the child, with its position in the uterus, and also with the sensitivity of the walls of the uterus. In addition, many women perceive the increased work of the intestine as the movements of the child. In addition, expectant mothers often have increased gas formation.
Determination of the gestational age by weeks when examined by a doctor
When a pregnant woman comes to the doctor for the first time,The gynecologist examines it necessarily on the armchair. Survey helps determine what time frame, and identify existing problems. Good doctors accurately determine the duration of pregnancy (up to half a week), as well as the location of the fetus in the uterus. It is necessary to know that with a gynecological examination of a woman with a delay of 3-4 weeks, that is, in 5-6 weeks of pregnancy, there is a slight increase in the uterus. Its size is approximately equal to a chicken egg. And at the 8th week the uterus already has the size of a goose egg. At 10 weeks of pregnancy, it is the size of a female fist. After 12-14 weeks, the doctor without problems determines the size of the uterus. In this case, we are talking about the length of the uterus during the examination of the woman on the couch. Thus the gynecologist uses centimeter tape. 
How to determine how many weeks of pregnancy, monthly
The definition of the term for a month is called obstetric. How is it calculated? Find out how many weeks, it is not difficult, because in this case the period of ovulation is not taken into account. The duration of menstruation is also not important. The doctor must know the number of the first day of the last menstruation. It is from this date that the gynecologist starts counting the gestation period. For example, if you consult a doctor a week after the delay and are sure that the period is 3 weeks, the gynecologist will deliver 5 weeks.
Determination of the period of pregnancy by ultrasound
Typically, the first ultrasound scanis prescribed at 12-14 weeks of pregnancy. But at these weeks to establish its accuracy is difficult, because in all future mothers embryos develop the same way only in the first weeks after conception. Then the doctor can determine the time to within 1 day, in the absence of a heartbeat, clarify the location of the child. And if some deviations are detected during ultrasound, then a second trial is given in a week or 10 days for a more precise definition of pathologies and the elimination of a stagnant pregnancy. That is, it is possible to determine the term by ultrasound only in the early weeks. With the next two ultrasound, the doctor will put a term depending on the parameters of the child's body parts, his head. But do not forget that the second half of pregnancy is the individual development of children. After all, it is normal to give birth to boys and girls weighing 2800 g and 4000 g in time 
How to determine the gestation period for hCG
Human chorionic gonadotropin (hCG) is oneof the important indicators of the presence of pregnancy, its normal course. HCG is a hormone produced in the body of a woman after inserting a fetal egg into the uterine wall, that is, after embryo implantation. This occurs already on the 6th-8th day after the fertilization of the female egg. The presence of this hormone in the blood and urine forms the basis of pregnancy testing. The usual tests, sold in pharmacies, determine the presence of this hormone in two strips. This hormone in the first trimester stimulates the production of estrogens and progesterone - the two female hormones needed to maintain the normal course of pregnancy. In the first weeks, the hCG level doubles about every 2-3 days. Increasing it by 60% in 2 days is the norm. The longer the period becomes, the less the growth of hCG level. At 8-9 weeks of gestation, the hCG level does not increase. On the contrary, it begins to decline at a slower rate. By the way, in case of multiplicity, the level of the hormone increases depending on the number of fruits. If 2 fetuses, then the level of hCG will be 2 times higher than normal. Common, standard norms of this hormone are considered the main determinants of this term. It should be borne in mind that the period for hCG does not coincide with obstetric. This is because the pregnancy according to the chorionic gonadotropin is ascertained relative to the day of conception. It displays the age of the unborn child. But the obstetric calculations are determined by the doctor regarding the date of the last menstruation and are not related to the day of conception of the baby. So, with all listed variants it is quite possible to accurately determine the duration of pregnancy. Nevertheless, it is worth considering that even at the most correct calculations a child can appear before and after. Therefore, the main task of the future mother is to do everything possible for the normal course of pregnancy and the safe appearance of the baby.
