Determining the gestational age and the date of the expected birth is of great practical importance. Knowing them, you can monitor the development of the fetus in dynamics, diagnose possible complications of pregnancy (for example, premature birth), and also be able to provide timely prenatal leave.
Instructions
Step 1
One way is to determine by the date of the last menstruation. However, this method can only be used in women with a regular menstrual cycle. Otherwise, calculation errors are possible. Take your personal calendar and count how many weeks have passed since her first day. This will be the gestational age. The Negel formula is used to determine the date of the expected birth. Count 3 months back from the first day of your period and add 7 days to them.
Step 2
You can find out the duration of pregnancy and childbirth by the date of ovulation. Ovulation occurs in the middle of the cycle, usually at 12-16 days, if you count from the first day of menstruation. More often it is during this period that conception occurs. From the selected moment, count the gestational age and add 2 weeks. To find the due date from the ovulation date, subtract 3 months and 7 days, or add 38 weeks. This method is ideal for women who become pregnant artificially.
Step 3
The gynecologist can determine the gestational age according to the data of the vaginal examination. It determines the size of the uterus, which gradually increases in size. At a later date, the uterus is well felt through the abdomen, and the doctor measures the volume of the abdomen and the height of the fundus of the uterus above the bosom using a tape measure. It should be noted that this method is not always reliable. Often, the size of the uterus can be larger (with polyhydramnios, fibroids, multiple pregnancies) or less (with fetal malnutrition, oligohydramnios) of the prescribed norms.
Step 4
Another method is ultrasound examination (ultrasound). During the procedure, the size of the fetus is measured, which correspond to a certain period of pregnancy. The most accurate method is in the first trimester. In the subsequent time, errors in establishing the number of weeks of pregnancy are possible, tk. each growing fruit has its own constitutional characteristics. Sometimes the expectant mother and child may have some pathologies (for example, diabetes mellitus in a woman, fetal malnutrition), contributing to the delay in the growth and development of the embryo or its excessive growth.
Step 5
You can find the gestational age and the date of the expected birth by the first movement of the fetus. Usually, a primiparous expectant mother feels it at 20-21 weeks of pregnancy, a multiparous one - already from 18-19 weeks. To calculate the gestational age, add 5 lunar months to the date of the first movement. If the birth is the second - 5, 5 months.
