Maternal-Fetal Medicine

Maternal-fetal medicine (MFM), also known as perinatology, is an obstetric subspecialty focused on the management of high-risk pregnancies — those complicated by maternal medical conditions, fetal abnormalities, or a history of adverse obstetric outcomes. MFM specialists complete OB-GYN residency followed by a three-year fellowship, equipping them with advanced skills in prenatal diagnosis and complex obstetric management. Maternal medical conditions complicating pregnancy include chronic hypertension, pregestational diabetes, cardiac disease (including congenital heart disease in increasing numbers of women reaching reproductive age), autoimmune disorders (lupus, antiphospholipid syndrome), obesity, and thyroid disease. MFM specialists co-manage these conditions with internists and subspecialists, balancing maternal health optimization against fetal safety of medications. Preeclampsia — the hypertensive disorder unique to pregnancy — affects 5–8% of pregnancies and is a leading cause of maternal and perinatal morbidity. MFM specialists manage severe preeclampsia with magnesium sulfate for seizure prevention, antihypertensive therapy, and — when indicated — delivery planning that optimizes gestational age against the risks of continuing the pregnancy. Prenatal diagnosis encompasses first-trimester screening (nuchal translucency, cell-free fetal DNA), second-trimester anatomy ultrasound, amniocentesis, and chorionic villus sampling (CVS). Fetal abnormalities diagnosed prenatally allow for delivery planning at specialized centers and, in select cases, fetal intervention — including intrauterine blood transfusion for severe fetal anemia and in utero surgery for conditions like spina bifida (fetal MMC repair). Multiple gestation (twins, triplets) carries significantly elevated risks of preterm birth, selective fetal growth restriction, and twin-to-twin transfusion syndrome (TTTS) — the last treated with fetoscopic laser ablation of placental anastomoses.