Calculation of pregnancy period table

Many expectant mothers do not understand the pregnancy period table. The pregnancy period table plays an important role for women during pregnancy. It can help women sort out what they should do during the pregnancy period. It will also remind pregnant women of the specific time and content of prenatal check-ups. It can help expectant mothers acquire more pregnancy knowledge so as to better nurture the fetus. Let’s take a look at the relevant content of the calculation of the pregnancy period table.

Since it is difficult for every pregnant woman to accurately determine the time of conception, medical regulations stipulate that the expected date of delivery is calculated from the first day of the last menstrual period. The entire pregnancy period is 280 days, or 10 gestation months (each gestation month is 28 days). Pregnant women gave birth between 38 and 42 weeks of gestation, all of which were full-term. Since the length of each woman's menstrual cycle is different, it is normal for the estimated due date to differ from the actual due date by 1-2 weeks. The main calculation methods are as follows:

1. Calculated based on the last menstrual period:

Add 9 or subtract 3 from the month of the last menstrual period to get the month of the expected delivery date; add 7 to the day of the last menstrual period to get the day of the expected delivery date. For example: Ms. Zhang’s last menstrual period was March 13, 2008, and her expected date of delivery is approximately December 20, 2008. Ms. Li's last menstrual period was on May 28, 2008, so her expected date of delivery is March 5, 2009. The expected date of delivery can also be calculated from the first day of the last menstrual period to the 280th day.

2. Calculate based on fetal movement date:

If you can't 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. Calculate according to the basal body temperature curve:

The last day of the low temperature segment of the basal body temperature curve is regarded as the ovulation day, and the ovulation day is counted back 264-268 days, or 38 weeks.

4. Calculation based on B-ultrasound examination:

When doctors perform B-ultrasound, they can measure the biparietal diameter of the fetal head, the crown-rump length and the femur length to estimate the gestational age and calculate the expected date of delivery (this method is mostly used by doctors for B-ultrasound diagnosis).

5. Calculate from the time when morning sickness starts:

Morning sickness usually occurs at the 6th week of pregnancy, which is 42 days after the last menstrual period. The expected date of delivery is 280 days after the last menstrual period.

The above introduces in detail the calculation of the pregnancy periodic table. I believe that everyone must have a better understanding of the calculation method of the pregnancy periodic table, which will also be of certain help to pregnant women. The pregnancy periodic table reasonably and scientifically arranges what pregnant women should do during pregnancy. This is to better nurture the fetus and to regulate the health of the pregnant woman herself. Every expectant mother must arrange the content scientifically, eat more fruits and vegetables, and ensure the absorption of nutrients. If you want to know more about the periodic table, you can go to a regular hospital to consult relevant experts.