How to know the weight of the fetus

According to research in the medical field, the weight of the fetus in the middle and late stages of pregnancy is mainly derived from three major parameters.

Parietal diameter (BPD)

Abdominal circumference (AC)

Thigh bone length (FL)

The doctor explained that the parietal bone diameter is not the head circumference, but the length of the parietal bone diameter on both sides of the bone near the temple; the abdominal circumference should be measured on the same plane as the liver and stomach of the fetus; while the thigh bone appears on ultrasound, The shape is like a bone that a puppy loves to eat, and mothers-to-be can observe carefully through the display screen of the ultrasound.

These three parameters increase with the number of weeks of pregnancy, so a formula for predicting fetal weight can be obtained after synthesis.

After pregnancy, mothers-to-be are most afraid of their hungry babies, worrying that they will be malnourished and not healthy enough. But how do you know if the baby's weight in the mother's belly is just right? In order to remove the worries of expectant mothers, the next step is to reveal the secret of fetal weight for you!

Whether the fetal weight standard should be compared with the fetus of the same number of weeks

Is the weight of the fetus a standard, and what is the indicator? Who are you comparing to? The attending physician in the obstetrics and gynecology department explained that the weight of the baby in the mother's belly is compared with that of the fetus of the same number of weeks. Suppose a pregnant woman is 28 weeks pregnant. If you want to know whether her baby’s weight is standard, you have to gather expectant mothers who are also pregnant at 28 weeks, find the average weight of the fetus in this group of pregnant women, and then compare this How much is the difference between a pregnant woman and this average, so different averages will appear for different weeks of pregnancy.　The weight of the fetus is proportional to the number of weeks

However, it is impossible to gather pregnant women with different pregnancy weeks in the world, so now we need to estimate the weight of the baby in the belly by statistical measurement.

The doctor gave an example. The doctor used ultrasound to measure 5000 pregnant women at 20 weeks, 24 weeks, and 28 weeks of pregnancy. After measuring the weight parameters of the babies in their stomachs, they then plotted the number of weeks on the horizontal axis (X axis) and the vertical axis ( Y axis) is a graph of weight correlation. From this graph, it can be clearly observed that the weight of the fetus is directly proportional to the number of weeks of pregnancy and rises in a positive correlation.

Default weight (EBW) = proportion of double parietal diameter × double parietal diameter (BPD) + proportion of abdominal circumference × abdominal circumference (AC) + proportion of femur length × femur length (FL) ± 15% difference

Predict the range of weight drop

Prenatal ultrasound is used to estimate the weight of the fetus. Strictly speaking, it is a prediction of the weight drop point, so there will be errors. At present, the reasonable error is about ±15% of the estimated value. Assuming that the estimated weight is 2,000 grams, the weight of the fetus should fall between 1 700-2 300 grams, so the baby’s weight after birth only needs to fall on this Within the range, even if the estimate is accurate.

Because the weight of the fetus is measured by formulas derived from parameters, there is an error range and an applicable range of weeks. The doctor believes that the fetal weight measured before 24 weeks has a large error, so the prediction curve of fetal weight is not suitable for the fetus before 24 weeks. He recommends that mothers-to-be take the measurement in the middle and late stages of pregnancy, because only then will the fetus's weight be included in the indicators of growth and development, which is not only meaningful, but the results are more accurate.

Use the sonoline b fetal doppler to view the heartbeat of the fetus in the abdomen, observe the fetus at all times, and pay attention to his growth.