It is quite difficult to accurately determine the date of birth of a child, since it is difficult to establish the correct timing of ovulation and the date of fertilization. Pregnancy lasts an average of 280 days (40 weeks). Determination of the date of birth is based on the assumption that the pregnant woman had a 28-day menstrual cycle, and ovulation occurred on the 14-15th day of the cycle.
It is necessary
the calendar
Instructions
Step 1
The first way to determine the due date is the Negle formula. Add nine months and seven days to the date of the first day of your last period. A simple method of these calculations: from the first day of the last menstruation, they count three months ago and add seven days.
Step 2
You can determine the date of birth by counting 40 weeks from the first day of the last menstrual cycle.
Step 3
Another way: add 268 days to the estimated day of conception.
Step 4
The most accurate method for determining the duration of pregnancy is ultrasound (ultrasound) in the early stages of pregnancy. After undergoing an ultrasound scan before 12 weeks of pregnancy, you can find out the date of conception with an accuracy of several days, and, based on this, calculate the approximate date of birth. In the second and third trimester, the probability of an error in determining the due date increases, this is justified by the characteristics of the development of the fetus.
Step 5
Pregnancy can be determined with a bimanual examination. A gynecologist can determine the duration of pregnancy by measuring the size of the uterus - determining the level or height of the fundus of the uterus, the circumference of the abdomen. At 4 weeks of gestation, the uterus is about the size of a chicken egg, at 8 weeks - about the size of a goose egg. At 12 weeks, the uterus grows to the size of a man's fist, the fundus of the uterus reaches the upper edge of the pubic bone. At 16 weeks of gestation, the fundus of the uterus is in the middle of the distance between the bosom and the navel, and at 24 weeks it is at the level of the navel. The uterus acquires the largest size at 36 weeks (the abdominal circumference reaches 90 cm), by this time the bottom of the uterus rises to the ribs, and then by 40 weeks it drops a couple of centimeters. The lowering of the uterus means that the baby is already preparing for childbirth.
Step 6
Also, the estimated date of birth is determined by the first movement of the fetus. In primiparous women, this usually occurs at 20 weeks, and in multiparous women from 18 weeks of gestation.
