Dictionary.net

the branch of obstetrics concerned with the anatomy and physiology and diagnosis and treatment of disorders of the mother and the fetus or newborn baby during late pregnancy and childbirth and the puerperium

the branch of obstetrics concerned with the anatomy and physiology and diagnosis and treatment of disorders of the mother and the fetus or newborn baby during late pregnancy and childbirth and the puerperium

The branch of medicine dealing with the fetus and infant during the perinatal period. The perinatal period begins with the twenty-eighth week of gestation and ends twenty-eight days after birth. (From Dorland, 27th ed)