Obstetrician/Gynecologist (OB/GYN) Email Lists: As the name implies, an obstetrician/gynecologist is a doctor who combines two different medical specialties into one. An obstetrician specializes in treating pregnant women, laboring mothers, and children after birth. Gynecologists are doctors specializing in female reproductive health. Physicians who specialize in treating high-risk pregnancies are called primatologists. Oncologists specializing in treating cancers of the ovaries and uterus are called gynecologic oncologists.