Diagnostic ultrasound in pregnancy: an overview.

The safety of ultrasonography in pregnancy is well documented. In screening populations, with the exception of the RADIUS trial, ultrasound examination can diagnose in approximately 50% of major anomalies. The accuracy of anomaly detection improves with increasing operator experience and advances in equipment resolution of the fetal image. The effect of routine sonography on perinatal outcome in low-risk pregnancies has not been established. Therefore, the role of ultrasound in routine screening remains controversial. However, in high-risk populations the accuracy of ultrasound in diagnosing congenital anomalies is well over 90%. The prenatal detection of abnormalities often influences obstetrical management and optimizes care of the fetus and newborn. The ability of ultrasound examination to determine gestational age, detect multiple gestations, and assess fetal well-being by diagnosing growth and fluid abnormalities has changed the practice of obstetrics more than any other technology in recent years.