Normally, at 16 weeks of pregnancy, the sex of the fetus can be determined by ultrasound, but this is not permitted by law in our country. Clinically, the week or month of pregnancy is calculated by taking 28 days as a month (which can also be understood as 4 weeks), and usually the sex of the fetus can be known by ultrasound at around 4 months of pregnancy, i.e. at 16 weeks. At the end of the 12th week of pregnancy, the external genitalia of the fetus has started to develop, and at the end of the 16th week, the gender of the fetus can be determined through the ultrasound section. However, during the examination it is also necessary to determine the sex of the fetus according to its fetal orientation. If the fetus is in a good position and there is no interference from the umbilical cord, the doctor will be able to accurately determine the sex of the fetus. At present, our law stipulates that it is illegal for doctors to privately identify the sex of the fetus through ultrasound, so all the parents-to-be, as long as the baby grows up healthily and happily, both boys and girls are the same, and you should put the baby’s healthy growth and development into the first place, and correctly look at the issue of men and women.