Is ultrasound estimation of fetal weight accurate?

If you want to know the size of the fetus, you can check it through the current three-dimensional color ultrasound, but it is more troublesome to know the weight of the fetus. After all, there is no way to know it by weighing it. However, in clinical medicine, the weight of the fetus can still be calculated through B-ultrasound. Although this calculation method is scientific, the test results may not be completely accurate and can usually only be used as a reference.

Is ultrasound estimation of fetal weight accurate?

With the development of technology, many pregnant mothers want their children to be in a healthy state, so they will naturally go to the hospital for some ultrasound examinations. For example, B-ultrasound can show the development of the child in the belly, the gender and the development of various organs, and sometimes the fetal weight can be measured. So, is B-ultrasound accurate in predicting fetal weight?

Is B-ultrasound accurate in predicting fetal weight?

Obstetric ultrasound begins measuring fetal weight after 28 weeks of pregnancy because estimating the fetus is not very meaningful before 28 weeks of pregnancy. During this period, the growth and development of different fetuses are roughly the same, and the doctor can judge whether the fetal development is consistent with the gestational age based on certain ultrasound indicators. After 28 weeks of pregnancy, the development of different fetuses gradually becomes different. For example, some have big heads, some have long legs, etc., and it is difficult to correctly assess the overall development. 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.

As the fetus in the abdomen continues to develop and grow, the doctor can use B-ultrasound to measure the head circumference, abdominal circumference and femur length of the fetus in the abdomen to further determine the size of the fetus in the abdomen and assess the weight of the fetus. In fact, there are errors in the measurement process. Sometimes errors may occur due to the curling posture of the fetus or the different size and structure of the skeleton. The measurement formula is approximately fetal weight = 260.69XHC-4973.72. HC stands for the head circumference of the fetus.

The doctor said that the characteristics of a boy

In the early stages of pregnancy (January to March), the pregnancy reaction was relatively weak, and I basically did not vomit. But sometimes I felt very nauseous. I would feel nauseous when I saw meat, especially pork liver. I couldn't even smell it. I like sour and sweet foods and I basically don’t feel nauseous during the second trimester. The pregnancy was obvious quite early, around 50 days into the pregnancy, the old pants could no longer be worn, but the belly shape became more and more typical, guessing it was a boy's belly, with a low and pointed belly, no bulging belly button, a clear line in the middle of the belly, thin above the belly button but to the left, thick and straight below the belly button, and a somewhat B-shaped belly.