Maternal–fetal medicine (MFM), also known as perinatology, is a branch of medicine that focuses on managing health concerns of the mother and fetus prior to, during, and shortly after pregnancy.Maternal–fetal 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 pediatricians or neonatologists. For the mother, perinatologists assist with pre-existing health concerns, as well as complications caused by pregnancy.Maternal–fetal medicine began to emerge as a discipline in the 1960s. Advances in research and technology allowed physicians to diagnose and treat fetal complications in utero, whereas previously, obstetricians could only rely on heart rate monitoring and maternal reports of fetal movement. The development of amniocentesis in 1952, fetal blood sampling during labor in the early 1960s, more precise fetal heart monitoring in 1968, and real-time ultrasound in 1971 resulted in early intervention and lower mortality rates. In 1963, Albert William Liley developed a course of intrauterine transfusions for Rh incompatibility at the National Women's Hospital in Australia, regarded as the first fetal treatment.  Other antenatal treatments, such as the administration of glucocorticoids to speed lung maturation in neonates at risk for respiratory distress syndrome, led to improved outcomes for premature infants.