Perinatal medicine is a branch of medicine that focuses on managing health concerns of the mother and foetus prior to, during, and shortly after pregnancy. Perinatal medicine specialists are physicians who subspecialize within the field of obstetrics. Their training typically includes a four-year residency in obstetrics and gynecology followed by a three-year fellowship. They may perform prenatal tests, provide treatments, and perform surgeries. They act both as a consultant during lower-risk pregnancies and as the primary obstetrician in especially high-risk pregnancies. After birth, they may work closely with paediatricians or neonatologists. For the mother, perinatologists assist with pre-existing health concerns, as well as complications caused by pregnancy.