The placenta generally begins to form 2-3 weeks after fertilization and is fully formed at about 12 weeks of gestation. The development of the placenta is a gradual process. When the embryo develops to about 13-21 days, the main structure of the placenta, the chorion, begins to form, and the fetal placental circulation is established around the third week after fertilization. The placenta is attached to the uterine wall and connected to the fetus through the umbilical cord. During pregnancy, the placenta can synthesize a variety of hormones, enzymes and cytokines, which are important for maintaining a normal pregnancy, and it has the function of material exchange, supplying the fetus with nutrients and helping to discharge the fetus’ metabolic waste. If the placenta is underdeveloped, it is likely to cause fetal growth retardation and intrauterine hypoxia. It is recommended that pregnant women in early pregnancy pay attention to rest, avoid staying up late and fatigue, pay attention to nutritional supplements, maintain a balanced diet and regular maternity checks.