A pregnant mother’s belly button is a depression formed by the abdominal muscles and has no substantial effect on fetal development and is not attached to the fetus. The fetus completes its growth and development in the pregnant mother’s uterus and is attached to the placenta through the umbilical cord, which is attached to the wall of the pregnant mother’s uterus. The placenta has two umbilical arteries and one umbilical vein, which is the pathway for the fetus to obtain nutrients and excrete metabolites from the mother, as well as being able to exchange gases and provide oxygen to the fetus. The placenta is a tissue formed by the embryonic membrane of the embryo and the endometrium of the mother’s uterus, which can provide nutrition to the fetus and at the same time has a barrier effect on some bacteria and microorganisms, i.e. the placenta produces nutrients and then supplies them to the fetus through the umbilical cord connection to ensure the growth and development of the fetus. Therefore, we should actively improve all pregnancy examinations during pregnancy, and we can observe the development of placenta and umbilical cord through ultrasound to ensure the normal growth and development of the fetus.