It is important to know the weight of the fetus during pregnancy in order to assess whether the development is appropriate for the gestational age. Also, the weight must be observed if the expectant mother has a narrow pelvis, since it will be difficult to give birth with a large fetus in such a situation.
It is necessary
- - tape measure;
- - calculator;
- - visit to the office of ultrasound diagnostics;
- - access to the Internet.
Instructions
Step 1
The first method of calculation is a calculation based on the girth of the abdomen and the height of the fundus. Take measurements lying on your back, the bladder must be emptied. Measure the girth of the abdomen with a measuring tape at the level of the navel, and the height of the fundus of the uterus - from the upper edge of the bosom to the fundus of the uterus.
Step 2
The weight of the fetus is calculated using 3 formulas, and then the average value is calculated, which will be equal to the approximate weight of the fetus. The following formulas are used (A - abdominal girth, B - uterine fundus height):
1) (A + B) * 25
2) A * B
3) (B - 12 or 11) * 155
In the last formula, the number 11 is used if the wrist circumference on the non-working hand is less than 16 cm, and 12 if more than 16 cm.
Step 3
It is important to note that this method of calculating the weight of the fetus has at least some degree of reliability only in the late stages, starting from 38-39 obstetric weeks of pregnancy, when the child reaches such a size that the volume of amniotic fluid can be neglected. In addition, this method has a very large error - at least 400 g.
Step 4
The second option is considered more accurate. In this case, the calculation of the weight of the fetus is based on ultrasound (ultrasound) data. The weight is calculated by the program built into the ultrasound machine. The formula by which the program calculates is based on experimental and statistical data and also has a significant error.
Step 5
The doctor will write down the weight calculated by the device in your examination protocol. If, for some reason, the doctor did not indicate the weight, then you can use the Internet resources. On many sites dedicated to pregnancy and childbirth, you can find programs that will calculate your baby's weight when you specify the necessary parameters.
