Prenatal detection of congenital malformations by ultrasonography. Mayo Clinic experience.

Routine obstetric ultrasonography has been performed at our institution since 1974. During a recent 41-month period, 64 neonates with 83 congenital abnormalities had been scanned before delivery. The detection rate according to the organ system involved and the year in which the study was performed is reviewed. Suggestions, based upon the data presented, are given for the various anatomic sites and fetal dimensions that should be evaluated during each stage II ultrasound examination.