Is the due date 38 weeks or 40 weeks?

Generally speaking, the due date should be calculated from the first day of bleeding during the expected period of pregnancy. The entire pregnancy period is 280 days, and each pregnancy month is 28 days and 4 weeks, that is, 10 months, 40 weeks. Therefore, it is also called the ten-month pregnancy. The method for calculating the expected date of delivery is as follows:

If the expected date of delivery is more than 3 months, subtract 3 from the month and add 7 to the time; if it is less than 3 months, add 9 to the month and add 7 to the time. You can also add 280 days immediately. This is all about gestational age. For example, if the due date is September 2, 2017, then the due date is June 9, 2018.

Will the due date be calculated?

Of course, it’s okay if you don’t remember the due date. You can determine the number of weeks of pregnancy based on ultrasound data. This is the gestational age, which refers to the time of fertilization. The gestational age is generally 266 days, which is a more accurate method. Because the size of the fetal sac, the length from the fetal head to the buttocks, and the standard value of the parietal diameter on both sides of the fetal head can be calculated, the gestational age and delivery date can be calculated from these values. There is a two-week gap between the gestational age and the due date. Therefore, if you know the gestational age, adding 14 days will give you the gestational age, and the due date is the same.

Will the due date be calculated?

However, ultrasound examination will be more accurate in calculating gestational age in the early stages of pregnancy, but the success rate will be lower if the pregnancy exceeds 10 weeks.

If the due date is missed, the above methods cannot calculate the due date. You can calculate it according to the time of the first fetal movement, which is usually 18 to 20 weeks of pregnancy. Add 20 to 22 weeks directly, and the time obtained is the due date.

It can also be determined by the size of the uterus: the gestational age is measured based on the height-to-width ratio of the uterine fundus.

In fact, no matter which method is used to calculate, the delivery dates are not likely to be far apart. In addition, pregnant women will experience symptoms such as spotting, rupture of amniotic fluid, and regular pain before giving birth. When the due date is approaching, expectant mothers should be prepared for childbirth at any time.

Therefore, it is best to use the due date of pregnancy as the standard for calculating the due date. This method is very simple and therefore common.