Ultrasound in the diagnosis of congenital anomalies.

With high-resolution ultrasound equipment, it is now possible to diagnose certain fetal anomalies in the third trimester and in some cases before the twentieth week of gestation. During a 27 month period 2,548 ultrasound scans were performed in high-risk patients. An anomaly was diagnosed in 10 of 122 second-trimester patients who were at risk for recurrent fetal defects. Fetal deformity was also found in 26 third-trimester patients. Of the 2.8% of patients found to have polyhydramnios 18% were associated with various types of anomaly. With ultrasound it was possible to examine internal fetal anatomy and to identify abnormalities of the fetal cranium, spine, chest, abdomen, and limbs. These anomalies are reviewed here in detail. Based on ultrasonically derived information, second-trimester patients can be offered information concerning the status of their fetuses at risk genetically and physicians can better manage third-trimester patients with diagnosed fetal deformities.