Obstetrics and gynecology is the medical specialty that deals with pregnancy, childbirth, and the postpartum period and the health of the female reproductive systems and the breasts. Obstetrics and gynecology is the medical specialty that deals with pregnancy, childbirth, and the postpartum period and the health of the female reproductive systems and the breasts. Obstetrics and gynecology is the medical specialty that deals with pregnancy, childbirth, and the postpartum period and the health of the female reproductive systems and the breasts.