When two people have intercourse, a fertilized egg is formed after fertilization of the sperm and the egg, which is transported through the fallopian tube and implanted into the uterine cavity to develop into a blastocyst, which enters the pregnancy period, during which regular maternity exams must be performed after pregnancy. The first maternity checkup is done around 50 days after menopause with ultrasound to determine if the pregnancy is intrauterine. During the second check-up, early Down’s syndrome screening and basic maternal condition determination, such as liver function, coagulation analysis, and hepatitis B, syphilis and HIV tests, are done at 11-13 weeks. At around 20 weeks, mid-term screening and 4D ultrasound screening will be done. At 28-32 weeks, a second maternal assessment is performed, such as diabetes screening, liver and kidney function and screening for mid- to late-term fetal malformations. After 32 weeks, occasional fetal safety monitoring will be performed.