There are three major processes of fetal development in pregnancy, early pregnancy, middle pregnancy, and late pregnancy. Early pregnancy refers to the first trimester of pregnancy, which includes the union of sperm and egg to form a fertilized egg, gestational sac and embryo. In the early stage of pregnancy is the dangerous period, it is necessary to take proper bed rest, avoid exertion and cold, monitor the fetal heartbeat, fetal bud and progesterone value, and follow the doctor’s advice for supplementation if there is any deficiency. In the middle of pregnancy, the fetus is mature and the ultrasound can see if there is any abnormality in each organ of fetal development. In the late pregnancy, you should avoid strenuous activities and have regular fetal heart monitoring and amniotic fluid depth check. During pregnancy, you should keep your mood relaxed, avoid anxiety and tension, listen to more soothing music, keep your pubic area hygienic and clean, and have regular pre-pregnancy checkups.