Obstetricians (also called OBs) are medical doctors who specialize in the care of pregnant women, from the time of conception through delivery and the period following delivery (postpartum). Most obstetricians are also gynecologists who diagnose and treat diseases of the female reproductive system and provide care for women when they are not pregnant.

An obstetrician can further specialize in perinatology (maternal-fetal medicine), which focuses on high-risk pregnancies, testing, and fetal development. Or an obstetrician may specialize in reproductive endocrinology and infertility (care of women who have hormonal or fertility problems).

Obstetricians are certified by the Royal College of Physicians and Surgeons of Canada.