Obstetrician/gynecologist: An obstetrician is a physician who delivers babies and is in the practice of obstetrics while a gynecologist is a physician who specializes in treating diseases of the female reproductive organs. The word "gynecology" comes from the Greek "gyno, gynaikos" meaning woman + "logia" meaning study, so gynecology literally is the study of women. These days gynecology does not address all of womenÆs medicine but focuses on disorders of the female reproductive organs. An obstetrician/gynecologist is thus a physician who both delivers babies and treats diseases of the female reproductive organs. Abbreviated commonly as OB/GYN.