How to determine the exact time of pregnancy

For pregnant women, knowing their pregnancy time is a very important thing. In medicine, it is required that the expected date of delivery be calculated from the first day of a pregnant woman's last menstrual period. The normal gestation period for pregnant women is about 40 weeks, which is 10 gestational months, and each gestational month is 28 days. If a woman's menstrual cycle is 28 days, then the gestational period of 280 days is equal to ten gestational months, hence the term "ten months of pregnancy". Generally, women ovulate in the middle and late stages of their menstrual period, and starting from the day the egg is fertilized, the normal pregnancy period for pregnant women is about 265 days. Therefore, the 40-week pregnancy period is 2 weeks longer than the actual pregnancy day calculated from the beginning of egg fertilization.

Pregnant women will give birth between 38 and 42 weeks of pregnancy, but the expected date of delivery is only an estimate. The specific delivery time and the expected date of delivery can vary by 1 to 2 weeks. There are four ways to calculate the expected date of delivery, namely general optimization algorithm, baby fetal movement measurement, morning sickness reaction measurement and B-ultrasound measurement.

1. General optimization algorithm. Start calculating from the first day of the pregnant woman's last menstrual period, add nine or subtract three from the month, and add seven to the time, which is the approximate value of the expected delivery date.

2. How to calculate baby's fetal movement. If you really can't remember the time of your last menstrual period, you can calculate the expected date of delivery based on the time of fetal movement. Generally speaking, fetal movement begins between 18 and 20 weeks of pregnancy. The calculation method is: for first-time mothers, it is the day when the baby moves plus 20 weeks; for primiparas, it is the day when the baby moves plus 22 weeks.

3. Methods for calculating morning sickness reactions. Generally speaking, morning sickness occurs in the sixth week of pregnancy, which is 42 days from the last menstrual period, and 280 days after the start of morning sickness is the expected date of delivery.

4. B-ultrasound measurement method. When the doctor performs B-ultrasound on the pregnant woman, the biparietal diameter, brachiocephalic diameter and femoral head length of the fetus are measured to calculate the fetal uterine development time and the expected delivery date. Pregnant mothers should pay close attention to their physical condition, and go to a reliable hospital for detailed examinations regularly to protect the health of themselves and their fetuses.