Fetal weight can be estimated by ultrasound, pregnant women’s uterine height and abdominal circumference, and professional software, but these calculations and measurements may have certain errors. 1. Ultrasound: Pregnant women can measure the fetal biparietal diameter, femur length, head circumference and abdominal circumference through abdominal ultrasound for fetal weight calculation, but these data are easily affected by human subjective factors and may have errors. 2. Pregnant women’s uterine height, abdominal circumference: through the examination of pregnant women, measuring pregnant women’s uterine height, abdominal circumference, you can also calculate the weight of the fetus, but this measurement method is easily affected by the thickness of the abdominal wall fat of pregnant women. 3. Professional software: some professional software for calculating fetal weight can also roughly estimate the weight of the fetus, but these software also need to enter some data, and there may be errors. If you need to observe the condition of the fetus in detail, it is recommended to consult a doctor in time and have the appropriate examination under the doctor’s guidance.