Placental cysts generally grow appropriately with fetal growth and require close monitoring of fetal and placental function. Placental cysts are benign tumors of the placenta, most of which are small in size and can be located on either the maternal or fetal side of the placenta, and will grow appropriately as the fetus grows, generally without affecting fetal growth and development. However, there are a few placental cysts that may increase significantly in size, thus affecting the function of the placenta and the growth of the fetus, and need to be closely monitored under the guidance of a doctor. In clinical practice, when the ultrasound examination suggests that there is a placental cyst, fetal growth and development and placental function is normal, under the guidance of the doctor, dynamic observation of the growth of the cyst and the function of the fetus and the placenta. It is also important to avoid strenuous exercise during pregnancy. After delivery, the placenta should be sent for pathological examination to clarify the nature of the cyst, and the corresponding treatment should be given according to the doctor’s instructions.