Gynaecology also known as Obstetrics and Gynecology is usually abbreviated as Obs and Gynae, O&G, OB-GYN or OB/GYN is the medical specialty that encompasses the two subspecialties of obstetrics – covering pregnancy, childbirth, and the postpartum period and gynecology – covering the health of the female reproductive system – vagina, uterus, ovaries, and breasts.