Prenatal diagnosis of major congenital malformations

Congenital malformations affect approximately 2-3% of all live births every year. Several of these are associated with in-utero fetal demise or may account for significant neonatal morbidity and mortality. Therefore, it is important that, when possible, congenital anomalies are diagnosed during the antenatal period to allow adequate counseling of the mother and to permit preparation of the neonatal care team to optimize the outcome. The role of ultrasound in perinatal medicine has expanded over the past two decades. Previously, B-mode sonography allowed for the detection of multiple gestations, fetal biometry, and basic antenatal diagnosis of congenital anomalies. The technology has since rapidly advanced to the point that even subtle abnormalities are amenable to antenatal diagnosis. Perinatal medicine has advanced concurrently with these technological breakthroughs, and as a result, the possibilities for in-utero therapy and potential surgery have markedly improved. This article reviews the types and incidences of the various anomalies that are detectable by antenatal ultrasonography using a systematic approach; highlights the prenatal diagnostic and therapeutic strategies; discusses the obstetrics and medical management of pregnancies complicated by these conditions, and presents the neonatal prognosis and the recurrence risks for subsequent pregnancies.