How do I calculate my due date? How do I calculate my due date?

Calculation method: Calculate from the first day of the last menstrual period, subtract 3 from the month, add 9 if it is not enough, and add 7 to the number of days. If your last menstrual period was June 29, 2011, the expected date of delivery should be April 6, 2012 if the month is subtracted by 3 days plus 7.

If you can't remember the date of your last menstrual period, you can make an approximate calculation based on the date of fetal movement. Generally, the date of fetal movement is about 18-20 weeks after pregnancy, and the approximate due date can be calculated by adding 20 weeks.

If there are conditions for ultrasound measurement of some diameters of the fetus's body, the gestational age can be measured, and the expected date of delivery can be calculated from this.

The above calculation of the expected date of delivery is often 1-2 weeks different from the actual date of delivery, if the length of the usual menstrual cycle changes greatly, the expected date of delivery can be more different, the estimated date is an approximate number, and it is normal to give birth within 2 weeks before and after the expected date of delivery.

The due date of delivery is calculated by menstruation and the size of the fetus by ultrasound.

If the last menstrual period is January 1st, the month is added by 9, that is, the expected date of delivery is September, and the month date of January 1 is added to 7, that is to say, the last menstrual period is January 1st, and our expected date of delivery should be October 8th.

There is also a kind of pregnancy women with irregular menstruation, which can only be speculated by B-ultrasound.

From the size of the fetus in the first trimester, the gestational age of the fetus is used to reverse the expected date of delivery, and this situation is calculated by ultrasound. Therefore, B ultrasound must be accurate, and the expected date of delivery must be verified repeatedly, so as to avoid the situation that the due date is delayed more and more advanced, which will have an impact on the fetus.

Textbook method for estimating the expected date of delivery:

The month of the last menstrual date plus 9 or minus 3 is the number of months of the expected date of delivery; The number of days plus 7 is the expected date of delivery.

Let's take an example: the last menstrual period was on June 8, 2020, then.

Month: June-3=March (2021);

Date: 8 days + 7 = 15 days;

Due date: March 15 (2021).

And actually, most of usThe expected date of delivery is derived from the ultrasound estimation of gestational age. The best time to estimate the gestational age in the first trimester is around 10-13 weeks, and the best time in the second trimester is 18-20 weeks.

Below we make three types of due date estimation methods according to the different pregnancy conditions, and pregnant mothers can sit in the right seat

(1) In the first trimester (before 13+6 weeks of pregnancy), the use of ultrasound in the middle bureau is the best way to estimate the gestational age.

1. Gestational age (weeks) = maximum diameter of gestational sac (cm) + 3.

2. Gestational age (weeks) = CRL (cm) +.

Note: CRL is reliable at 7-11 weeks, and BPD is more reliable after 12 weeks.

(2) If it is conceived by assisted reproductive technology, the gestational age determined by assisted reproductive technology should be used to calculate the expected date of delivery.

For example, gestational age and due date should be calculated from the date of IVF fertilization, and gestational age and due date can be calculated by the last menstrual period or the first accurate ultrasound, or a combination of both, and then discussed with the patient and recorded in the medical record.

IVF-ET embryo transfer day -17 = estimated time of the last menstrual period at gestational age (embryo transfer blastocyst minus 19).

For pregnant women who lack ultrasound in the first trimester, ultrasound before 22+6 weeks of pregnancy to estimate gestational age is the second best option.

Let's take a look at the baby's development at different gestational weeks.

8 weeks "little humanoid".

12 weeks, did you test NT?

At 18 weeks, is the baby moving?

24 weeks, 4 dimensions?

At 32 weeks, is the fetal monitored?

At 37 weeks, I'm full-term!

Add 280 days to the day of the last menstrual period, which is the calculation of 28 days of the menstrual cycle, and if it is 30 days, it is postponed by two days from the date calculated earlier.

In addition, there is a relatively simple algorithm, that is, the last month of the sale of the start time of the destruction of menstruation at 4 o'clock in the month, the expected date of delivery in the month 3, the date 7;At 3 o'clock in the month, the expected date of delivery is 9 in the month and 7 in the month

The calculation of the due date is actually very simple, it is calculated from the day of the mother's last menstrual period: the number of the last menstrual period plus 9 or minus 3 days plus 7, and your due date is calculated.

For example, if your last menstrual period is February 9th, then your due date is 11 (2 9) and 16 (9 7). This is the method of calculating the date of birth in the solar calendar. Delivery is normal for 2 weeks before and after the expected date of delivery.

According to the information you provide, your pregnancy and delivery date is on February 25, 2011, and the actual delivery date will have an error of one week or two weeks with the estimated due date. d

This is the due date**, you take a look.

Hello: The due date is calculated as the number of months of the last menstrual period plus 9 (or minus 3), and the number of days plus 7.

That is, from the first day of the last menstrual period, 9 natural months plus 7 days are the due date.

A full-term pregnancy lasts about 280 days (about 40 weeks) and is normal to give birth within two weeks before or after the expected date of delivery.

If the menstrual cycle before pregnancy is irregular, or the cycle is long, it is recommended to use the ultrasound examination, however, the ultrasound examination usually has an error of about a week.

Hello: The due date is calculated by adding 9 or minus 3 to the month of the first day of the last menstrual period to add the number of months of the expected date of delivery, and adding 7 to the solar calendar day to be the number of days of the expected date of delivery. The number of days in the lunar calendar plus 14 is the expected date of delivery. Generally, the difference between the actual secretion date and the estimated date is about one to two weeks. x

The due date is calculated as the number of months of the last menstrual period plus 9 (or minus 3) and the number of days plus 7.