The obstetrician-gynecologist is a specialist in the physiology of women, their reproductive system, pregnancy and childbirth and its consequences. Sexuality, contraception and cancer screening are among its areas of intervention. The gynecologist accompanies and monitors the pregnancy of pregnant women, during regular visits. He monitors the development of the embryo, then the fetus, and the impact of the latter on the mother-to-be, including ensuring that the cervix remains securely closed, and performing fetal examinations to detect risk of malformation. If necessary, he can offer a genetic examination by taking amniotic fluid. After a few months of pregnancy, the gynecologist can observe the sex of the baby using an ultrasound. If he is an obstetrician (surgery) in a hospital ward or clinic, he will supervise the delivery, often performed by a midwife. At the slightest problem, he intervenes: epidural (local anesthesia), incision of the perineum, cesarean section … He also monitors the consequences of childbirth on the health of the mother. a woman’s life: sexuality, contraception, tubal ligation … As a specialist in the fight against sterility, he can also use assisted procreation methods. In terms of prevention, it is again the gynecologist who monitors the cervix and ovaries to detect the slightest abnormality, and interprets mammograms to detect possible breast cancer.