How to calculate the fetal weight most accurately_What are the methods for estimating the fetal weight

As the pregnancy time of women increases, the fetus will develop slowly, which will lead to the continuous increase of the fetal weight. Many parents hope that the fetus can develop healthily and hope to understand the weight of the fetus. Especially after knowing the weight of the fetus before delivery, they can adopt the correct and safe delivery method to ensure the safety of pregnant women and fetuses. So how to calculate the fetal weight most accurately? What are the methods for estimating the fetal weight?

First, how to calculate the fetal weight most accurately? What are the methods for estimating the fetal weight? In the first 3 months of pregnancy, the fetal length (cm) is mainly calculated by measuring the distance from the fetal head to the hips. As the fetus develops, starting from the 15th week of pregnancy, the fetal head circumference or the diameter between the two parietal bones, abdominal circumference and thigh bone length are measured to determine the size of the fetus, and then the fetal weight (grams) 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.

Second, calculate the parameters of fetal weight. Parietal bone diameter (BPD), abdominal circumference (AC) and femoral length (FL) are three parameters that affect fetal weight. Parietal bone diameter (BPD). What is the parietal diameter? The parietal diameter is not the circumference of the head, but the length of the parietal diameter on both sides of the bone near the temple. Abdominal circumference (AC). What is abdominal circumference? Abdominal circumference is the distance between the fetal liver and stomach on the same plane: it is measured horizontally at the highest part of the abdomen. However, because the abdominal circumference of each expectant mother varies greatly, it is recommended that expectant mothers measure themselves regularly at home. Femoral length (FL). What is the femur length? On ultrasound, the shape of the femur is like the bones that puppies like to eat. Expectant mothers can observe it carefully through the ultrasound display. The expectant mother lies on her back, and the doctor uses a ruler to measure the length from the fundus of her uterus (near the position below her sternum) to the upper edge of the pubic symphysis, so as to estimate the growth of the fetus. When the pregnancy reaches more than 20 weeks, the number of weeks of pregnancy is usually equivalent to this distance. These three parameters increase with the number of weeks of pregnancy, so after combining them we can get a formula to predict fetal weight.

How to calculate fetal weight most accurately_What are the methods for estimating fetal weight? Formula for predicting fetal weight: Fetal weight (g) = 260.69*HC (head circumference)-4973.72. Formula 2 for predicting fetal weight: Fetal weight (g) = 171.48*AC (abdominal circumference) - 2686.60. Formula three for predicting fetal weight: Fetal weight (g) = 747.42*FL (femur length) - 2232.56. Formula 4 for predicting fetal weight: Fetal weight (g) = 1049.90*FTH (fetal leg subcutaneous fat thickness) - 2513.51. Formula 5 for predicting fetal weight: Fetal weight (g) = 100.97*HC (head circumference + 110.86*AC (abdominal circumference) + 143.09*FL (femur length) + 331.43*FTH (fetal leg subcutaneous fat thickness) - 5168.32. Formula 6 for predicting fetal weight: Fetal weight (g) = 900*BPD (biparietal diameter) - 5200. Formula 7 for predicting fetal weight: Fetal weight (g) = 0.3*uterine fundus height*chest circumference + 2900.