Is color Doppler ultrasound accurate in measuring fetal weight?

For the fetus in the body, they have a standard weight at different stages. In the early stages of pregnancy, they develop slowly, so the pregnant mother's belly does not look so obvious. In the late stages of pregnancy, the pregnant mother's belly will become particularly large, and the fetus will gradually develop completely. Generally, color Doppler ultrasound is used to measure the weight of the fetus. So is color Doppler ultrasound accurate in measuring the weight of the fetus?

Is the fetal weight on the ultrasound report accurate?

The weight of the fetus is an important basis for assessing the growth of the fetus. In the late pregnancy, the doctor will arrange for the expectant mother to undergo an ultrasound examination to assess the weight of the fetus, whether it is suitable for natural delivery, etc.

During the first three months of pregnancy, the fetal length (cm) is calculated mainly by measuring the distance from the fetal head to the hips. As the fetus develops, starting from the 15th week of pregnancy, the head circumference (HC) or the diameter between the two parietal bones (BPD), abdominal circumference (AC) and femur length (FL) are measured to determine the size of the fetus, and then the fetal weight (g) is estimated.

Since there is a large error in measuring the length of the fetus, for example, the curled posture of the fetus and the size of the skeleton may cause misjudgment of the results. Therefore, in medicine, weight rather than height is used as the basis for assessing fetal growth.

Measurement formula collection:

Formula 1: Fetal weight (g) = - 4973.72 + 260.69 × HC (head circumference);

Formula 2: Fetal weight (g) = - 2686.60 + 171.48 × AC (abdominal circumference);

Formula 3: Fetal weight (g) = - 2232.56 + 747.42 × FL (femur length);

Formula 4: Fetal weight (g) = - 2513.51 + 1049.90 × FTH (fetal leg subcutaneous fat thickness);

Formula 5: Fetal weight (g) = - 5168.32 + 100.97×HC (head circumference) + 110.86×AC (abdominal circumference) + 143.09×FL (femur length) + 331.43×FTH (fetal leg subcutaneous fat thickness);

Formula 6: Fetal weight (g) = 900 × BPD (biparietal diameter) - 5200;

Formula 7: Fetal weight (g) = 2900 + 0.3 × uterine fundus height × waist circumference.