There are differences in the time of onset of development of the fetal reproductive organs, mainly related to the sex of the fetus. In general, in male fetuses, the primordial gonads begin to differentiate at about 6 weeks of pregnancy, the testes develop at 9 weeks of pregnancy, and the external genitalia gradually form after 16 weeks of pregnancy. In female fetuses, the primitive gonads differentiate at about 8-10 weeks of pregnancy, the vagina, uterus, fallopian tubes and other reproductive organs are formed at 10-12 weeks of pregnancy, the external genitalia begin to develop at the end of the 12th week of pregnancy, the reproductive organs are basically formed at 16 weeks of pregnancy, and the reproductive organs are mature at about 33 weeks of pregnancy. Generally, the development of fetal reproductive organs can be seen through ultrasound examination at about 16 weeks of pregnancy, but now regular hospitals are prohibited to do non-medical gender identification. Pregnant women should eat more food rich in protein during pregnancy, such as eggs, lean pork, soy products, milk and so on. It is also necessary to properly supplement shrimp, fish, pork liver, oats, walnuts, peanuts and other foods, eat more fresh vegetables and fruits, to ensure that the intake of food nutritionally balanced, to avoid a single nutrition.