Normal female pregnancy cycle

Nowadays, young people know very little about the common sense of pregnancy, except for being happy and blessed after getting pregnant. In particular, many pregnant mothers-to-be are not very clear about this issue. They don’t know how long they have been pregnant. Even when they go for a prenatal check-up, they don’t know how to tell the doctor how long they have been pregnant. Let us learn about the female pregnancy cycle below.

After examination at the hospital, the doctor will help calculate the pregnancy period. There are two general methods for calculating pregnancy period:

One is calculated based on the date of the last menstrual period, and the other is calculated based on the date of sexual intercourse that caused pregnancy or the ovulation period.

The date of pregnancy is difficult for most people to remember and determine, so the pregnancy cycle is usually calculated based on the first day of the last menstrual period. The delivery date calculated based on the date of the last menstrual period actually takes the week of the last menstrual period as the first week of pregnancy. This means that you may not realize you are pregnant until your next menstrual period is late, but you have actually been pregnant for at least 2 weeks at this time.

The gestation period is generally about 280 days, which is 9 months and 1 week. The calculation method for the baby's due date is: pregnancy month + 9 (or -3), pregnancy date + 7.

For example: The last menstrual period was on November 28, 2014. The expected date of delivery is: November-March=August, 28th+7th=35th, which is September of the following year; 35th-31st=4th. The expected date of delivery is September 4, 2015.

If the menstrual date is not very accurate, you can measure the fetus by ultrasound or measure the height of the uterine fundus. Fetal movement can also be used to calculate the expected date of delivery. The first fetal movement for a first-time pregnant woman is around 18-20 weeks, and the due date may be 20-22 weeks later. By analyzing these pregnancy cycle calculation methods together, you can know the baby's expected delivery date.

Calculated from the date of delivery

Once a couple or even a large family confirms pregnancy, they will know when the baby will be born. Commonly known as "ten months of pregnancy", the gestation period of a pregnant woman is generally about 280 days (ie 40 weeks). Many people will ask how to calculate the due date, right?

There are several ways to estimate the due date:

1 Calculation after early pregnancy reaction

Some women have irregular menstrual cycles, or have forgotten the date of their last menstrual period, or have become pregnant again after giving birth or having an abortion but have not had their period yet. As long as they remember the time when early pregnancy symptoms such as nausea and vomiting occurred, they can use this to calculate the expected date of delivery. Since early pregnancy reactions usually occur around 6 weeks of pregnancy, the calculation formula is:

Due date = date of onset of early pregnancy symptoms + 34 weeks.

2Calculation of last menstrual period

If a pregnant woman has a regular menstrual cycle, she will have her period every 28-30 days and her last period is remembered accurately. You can use the formula to calculate: starting from the first day of the last menstrual period, subtract 3 or add 9 to the month, and add 7 to the day. If calculated according to the lunar calendar, the month should be added by 9 or subtracted by 3, and the date should be added by 14.

For example, if the first day of the last menstrual period is April 24, 2014, the expected date of delivery should be January 31, 2015; if the first day of the last menstrual period is April 24, 2014 in the lunar calendar, the expected date of delivery should be February 8, 2015 in the lunar calendar.

For women who have their period every three weeks, the pregnancy period should be 280 days - 1 week = 39 weeks.

For women who have their period every 4 weeks, the pregnancy period should be 280 days = 40 weeks;

For a woman who has her period every 5 weeks, her pregnancy period should be 280 days + 1 week = 41 weeks.

3 By date of intercourse that caused pregnancy

The 266th day from the date of sexual intercourse is the expected date of delivery.

4 Calculated by uterine fundus height

By comparing the measured uterine fundus height with the normal value table, the equivalent gestational age can be found. Add 40 weeks to this date to get the expected date of delivery.

Generally speaking, the actual delivery date may differ from the estimated due date by 1 to 2 weeks.

6 Calculated based on the date of fetal movement

The fetal movement of primiparas occurs around the 18th week of pregnancy. Multiparas, because of their experience, can feel the fetal movement 2 weeks earlier than primiparas, that is, at the 16th week of pregnancy. Therefore, the calculation formula is:

The expected date of delivery for a primipara = the date when fetal movement occurs + 22 weeks.

The expected date of delivery for a multiparous woman = the date of fetal movement + 24 weeks.

Pregnant women can calculate the date of their baby's birth by themselves through the above methods. In addition, if the pregnant woman has no early pregnancy reaction and has not felt fetal movement, and cannot remember the time of her last menstrual period, the doctor can use B-ultrasound and the height of the uterine fundus to help estimate the expected date of delivery.

7 Calculated by B-ultrasound

By measuring the gestational sac, fetal sitting height, biparietal diameter of the fetal head or fetal femoral length under B-ultrasound and comparing the measured values ​​with the normal value table, the equivalent gestational age can be found. Add 40 weeks to this date and the result is the expected date of delivery.

We have given you some simple explanations about the female pregnancy cycle. Every expectant mother should understand it very well. Only by knowing your own pregnancy cycle can you better understand the baby's development and know what you should pay attention to for the better development of the baby. Expectant mothers must make sure to go for regular prenatal checkups during pregnancy.