The size of the baby largely depends on how the delivery will take place, so to calculate the weight of the fetus for many future mothers becomes almost a top priority. Obstetricians-gynecologists use several formulas that allow you to calculate the estimated weight of the fetus from 32 weeks . It should be noted that the data of such calculations are relative, since they depend on a variety of features, including the anatomical structure of the mother, the amount of amniotic fluid, the position of the fetus in the uterus, and so on.
Formulas for weight determination:
- OZH x VDM
In this formula, the main values are the abdominal circumference and the height of the standing of the uterine fundus. For example, if at 32 weeks the abdominal circumference is 84 cm and the second figure is 32 cm, then the approximate weight of the fetus is 2688. It is worth repeating once again that the results of such calculations are relative, and the error can be up to 200-300 g.
- (OZH + VDM) / 4 x 100
This formula also allows you to calculate the weight of the fetus during pregnancy. For this, two indicators (abdominal circumference and height of standing of the uterus bottom) must be folded, divided by four and multiplied by one hundred. Thus, for given parameters, the weight of the fetus will be 2900 g.
- (VDM - 12 or 11) x 155
The third formula shows how to calculate the approximate weight of the fetus, taking into account the features of the physique of a woman. According to Solovyov's formula, a certain index is subtracted from the indicator of the standing height of the womb bottom (12 - if the circumference of the woman's wrist is more than 12 cm, 11 - if less), and then the number is multiplied by 155. As a result, for this example the weight of the fetus will be 3100 or 3255 gram depending on the structure of the body of the future mother.
Determination of the weight of the fetus by ultrasound
The most accurate data can be obtained if we calculate the weight of the fetus by ultrasound. Ultrasound examination allows you to determine not only the weight of the baby, but the correspondence of its individual sizes to the term of pregnancy. In order to calculate the weight of the fetus for weeks , there is a special calculator. If you enter all the ultrasound data, you can get the result that is closest to reality.
After counting by different formulas and taking into account the results of ultrasound, you can calculate the most accurate weight of the fetus at birth. It is worth remembering that each organism is individual, so if the results are higher or lower than the norm, it is too early to panic. As a rule, the norms can be strictly applied only to the first half of pregnancy, when the fetus is still very small, whereas in the third trimester the error can reach 500 g.