How to calculate the time of pregnancy?

We all know that pregnancy is very important for a family, but many times we don’t know how to calculate the time of pregnancy. If we don't calculate the time well, it may lead to us not taking good care of the health of pregnant women in our lives. For the health of pregnant women and fetuses, we need to have some knowledge in this area. Start by figuring out when you're pregnant. The following is a detailed introduction on the topic of how to calculate the time of pregnancy.

1. How to calculate the pregnancy time

1. The normal human gestation period is about 40 weeks. In medicine, the first day of the last menstrual period is often used as the starting time for calculating the expected date of delivery. The normal gestation period is about 265 days, which means it starts from the day the egg is fertilized. Ovulation occurs in the middle of the menstrual period, so 40 weeks of pregnancy is 2 weeks longer than the actual pregnancy time calculated from the egg fertilization.

2. If a woman's menstrual cycle is 28 days, then 280 days of pregnancy is equivalent to ten gestational months or ten menstrual cycles, hence the saying of ten months of pregnancy. The due date is only an estimate, and the actual delivery time often differs by 1-2 weeks.

2. Methods for calculating the expected date of delivery

1. Ordinary calculation method: start counting from the day of your last menstrual period! The expected date of delivery is calculated from the day of your last menstrual period, add nine or subtract three, and then add 7, this is the expected date of delivery.

2. Calculation of fetal movement: If you cannot remember the date of your last menstrual period, you can calculate it based on the date of fetal movement. Fetal movements usually begin between 18 and 20 weeks of pregnancy. The calculation method is: for primiparas, it is the day of fetal movement plus 20 weeks; for multiparas, it is the day of fetal movement plus 22 weeks.

3. Calculation of morning sickness: Morning sickness usually occurs at the 6th week of pregnancy, which is 42 days after the last menstrual period. Calculating backward from this to 280 days is the expected date of delivery.

4. Ultrasound calculation: When the doctor does ultrasound, he can measure the biparietal diameter, crown-rump length and femur length to estimate the gestational age and calculate the expected date of delivery.

3. Calculation formula for expected delivery date

The estimated date of delivery is calculated based on the entire gestation period of 280 days. The specific method is:

Estimated date of delivery = the month of the first day of the last menstrual period + 9 or -3.

Estimated date of delivery = the number of days from the first day of the last menstrual period + 7.

The time calculated in this way is the expected date of delivery. For example, if the last menstrual period was on February 1st, then month 2 + 9 = November, and day 1 + 7 = 8th, then the expected date of delivery should be November 8th.

If the last menstrual period was after April, subtract 3 from the formula. If the last menstrual period is on April 2, then April - 3 = January of the following year, 2 plus 7 = the 9th, so January 9th of the following year is the expected date of delivery. According to the above method, the expected date of delivery is calculated according to the Gregorian calendar. If the expected date is calculated using the lunar calendar, the month calculation is the same, except that the date plus 7 days is changed to 15 days.

The above is the specific knowledge about how to calculate the time of pregnancy. I hope these can help us all. In addition to understanding the duration of pregnancy, we also need to understand other care work for pregnant women during pregnancy. For the sake of these people's health, we must take care of all aspects of pregnant women's lives. Finally, I hope everyone can pay attention to the health issues of pregnant women!