How to correctly calculate the duration of pregnancy?
Ideal is the option, when the expectant mother accurately remembers the date when fertilization occurred, there was an unprotected sexual intercourse. In this case, just count the number of days that have passed. The resulting figure will be the true duration of the gestational period.
Answering the question of the fair sex relative to how correctly to count the gestation period, doctors recommend acting as follows:
- Precisely set the time of sexual intercourse, if it is impossible to do this - remember the number of the first day of the observed menstruation.
- Calculate the past calendar day.
Obstetrical gestational age
Widely used by gynecologists, since it does not require additional equipment. To calculate the duration of pregnancy for a month, you need to know the number of their first day. Using it causes difficulties for women with a violation of the cycle (irregular discharge). Then for accuracy of calculation it is possible to resort to other methods of calculation. Usually it differs from the actual one for 2 weeks (before the day of ovulation).
The real period of pregnancy
Calculated from a meeting of germ cells in the mother's body. To establish the length of the gestational period in this case, you can use accurate information about the time of ovulation. After it occurs the formation of a zygote. In the absence of the necessary information is used rarely. Calculation of the gestation period is carried out directly from the fertilization of the egg. After leaving the follicle, the female germ cell retains its viability for 24-48 hours. Then life begins. To calculate the duration of pregnancy so, is rather problematic.
Determination of gestational age
To calculate the duration of the current gestation, several methods are used:
- on the day of conception;
- by the number of previous menstrual periods;
- with the help of ultrasound;
- on the first stirring.
The extreme method is used at the end of the gestation to confirm the already established duration, as an additional control. In order to know the length of pregnancy, often resort to calculation for menstruation. In gynecology they call it obstetric, it is established directly by a specialist. Prevalence is explained by the difficulty of remembering the exact day when fertilization occurred.
Determination of the period of pregnancy by ultrasound
The most reliable technique is ultrasound. The earliest period for determining pregnancy by ultrasound is 4-5 days. On the monitor of the apparatus is diagnosed a fetal egg with a size of 1.5-3 mm. As it grows, it becomes easier to detect. Before counting the length of pregnancy, it is necessary to calculate the size of the embryo, and then compare them with the table. With the help of this method, they establish the developmental defects. In the presence of incompatible with life disorders, chromosomal abnormalities, medical abortion is prescribed, if not more than 42 days have passed. Later - use a mini-abortion.
For the entire time, ultrasound is performed at least three times:
- 12-14;
- 26-28;
- 32 weeks.
If the first two are conducted to assess the rate of fetal development, the formation of organs and systems, then the final study allows you to establish the position, condition of the placenta. Based on the data obtained, a tactic of delivery is developed.
How to determine the length of pregnancy for the last month?
To use this method, it is necessary to accurately remember the first day of the cyclic excretions noted before gestation. This can cause difficulty for those ladies who have an irregular cycle. In fact, determining the length of pregnancy by the date of the last month is a simple procedure. Partly therefore, this method is common among the fair sex.
According to physiology, the encounter of sex cells is possible only in ovulation, - the release of the egg from the follicle. The process occurs immediately in the middle of the cycle. If its duration is 28 days, then ovulation is noted after 14 from its beginning. For the starting point of the reference the physicians take the first day of cyclic bleeding. Obstetrical gestation period and real differ. The first does not reflect the true age of the embryo. In practice - more for 14 days.
Given this fact, midwives in calculating the duration of the current pregnancy, its length is taken for 40 weeks or 10 months. In fact, if you count from the day of sexual intercourse, it lasts about 38 calendar days. Consonant with the accepted norms, a full-term baby is born born after 37. It is said about the born when the baby is born after 42 weeks.