PILOT SCREENING FOR FETAL MALFORMATIONS - POSSIBILITIES AND LIMITS OFTRANSVAGINAL SONOGRAPHY

Two thousand and ninety-seven unselected pregnant women bearing 2114 f etuses were examined by transvaginal sonography at 14 weeks of gestati onal age and rescreened via transabdominal sonography at 21 weeks (exc luding those who chose termination of pregnancy). Twenty-five of 47 an omalies were correctly identified at the first scan, 15 malformations were missed and detected only during the scan, two were identified lat er in pregnancy, and five were identified after birth. Ten of 12 abnor malities were detected correctly on the basis of ultrasonographic find ings. Transvaginal sonographic screening for fetal malformation, in ou r experience, permits the detection of more than 50% of all fetal stru ctural defects and 75% of all aneuploidies early in pregnancy.