How to calculate the most accurate expected delivery date, with a list of calculation methods attached! During pregnancy, the expected delivery time is an important reference indicator. The accuracy of the expected delivery date directly affects the delivery time of pregnant women and the health status of newborns after birth. So, how is the most accurate calculation of the expected delivery date? Let's give a detailed explanation below.

1、 Common calculation methods for expected delivery time

1. Last menstrual cycle method

This is currently the most widely used method for calculating the expected delivery time. Specifically, the expected delivery date is calculated based on the first day and duration of the last menstrual period.

The specific calculation method is as follows:

(First day of last menstrual cycle+1 year) -3 months+7 days=expected delivery date

For example, if the first day of the last menstrual cycle is June 1, 2021, then the expected delivery date is March 8, 2022.

The advantage of this calculation method is that it is simple and applicable to most pregnant women. However, due to the different menstrual cycles of each individual, the accuracy of the expected delivery date can be affected to some extent.

2. Ultrasonic method

Measure fetal size, head circumference, and other parameters through B-ultrasound examination to calculate the expected delivery date.

Usually, a B-ultrasound examination is performed around 12 weeks, during which the size of the fetus can be accurately measured to determine the expected delivery date.

3. Double standard method

This method combines the last menstrual cycle method and ultrasound method, taking into account parameters such as the menstrual cycle of the pregnant woman and the size of the fetus to calculate the expected delivery date.

The commonly used specific calculation methods are as follows:

(First day of last menstrual cycle+1 year) -3 months+7 days+(gestational weeks measured by ultrasound× 7)=expected delivery date

For example, if the first day of the last menstrual cycle is June 1, 2021, and the gestational age measured by ultrasound is 12 weeks, then the expected delivery date is March 15, 2022.

2、 Factors affecting the accuracy of due date

1. Irregularity of menstrual cycle

If your menstrual cycle is irregular, there may be errors in the expected delivery date calculated using the last menstrual cycle method. At this point, it is best to use ultrasound or other methods to check the size of the fetus and calculate the expected delivery date more accurately.

2. Uncertainty of conception time

Under normal circumstances, sexual activity that occurs within two weeks after ovulation can easily lead to pregnancy. However, if the time of conception is uncertain, it is also difficult to determine the expected delivery date.

3. The situation of multiple pregnancies

For pregnant women with multiple pregnancies, the calculation of the expected delivery date is also more complex. At this point, multiple ultrasound examinations are needed to determine the size and growth status of each fetus, in order to calculate the expected delivery date more accurately.

4. Measurement errors in the middle and late stages of pregnancy

In the middle and late stages of pregnancy, due to significant changes in fetal size and posture, the accuracy of B-ultrasound measurement of the expected delivery date will also be affected to some extent.

3、 How can we obtain the most accurate expected delivery date?

1. Combining multiple methods to calculate the expected delivery date

In order to obtain a more accurate expected delivery date, multiple calculation methods can be combined, such as combining the last menstrual cycle method and ultrasound method, or using the double standard method.

2. Timely prenatal examination

During pregnancy, prenatal examinations should be conducted in a timely manner according to the doctor's requirements, including measuring the size of the uterus and the development of the fetus. These data can help doctors calculate the expected delivery date more accurately.

3. Pay attention to weight changes during pregnancy

The increase in body weight of pregnant women also has a significant impact on the calculation of the expected delivery date. Therefore, maintaining good dietary habits and appropriate exercise can control the weight changes of pregnant women and more accurately calculate the expected delivery date.

How to calculate the most accurate expected delivery date, with a list of calculation methods attached! The expected delivery time is an important reference indicator for pregnant women's delivery and fetal health management. By combining multiple calculation methods and conducting prenatal examinations in a timely manner, a more accurate expected delivery date can be obtained, and it can safeguard the health of pregnant women and fetuses.