PRENATAL SONOGRAPHIC FINDINGS IN 187 FETUSES WITH DOWN-SYNDROME

We determined the type and frequency of abnormal sonographic findings in 187 Down syndrome fetuses. Examinations were performed transvaginal ly or transabdominally between 9 and 28 weeks' gestation, Consecutive scans performed prior to knowledge of the fetal karyotype (n=144) were analysed separately for one of the participating centres. In 93 fetus es (49.7 per cent), a total of 138 abnormalities were observed. The mo st commonly detected anomalies were cystic hygroma and increased nucha l fold thickness (30.5 per cent), hydrops (9.6 per cent), cardiac defe cts (7.5 per cent), pyelectasis or hydronephrosis (5.9 per cent), echo genic bowel (4.8 per cent), and a large variety of internal organ abno rmalities (16.0 per cent) which are not typically associated With Down syndrome. Two anomalies or three anomalies in the same fetus were obs erved in 21 and 5 fetuses, respectively, No patterns of concurrent mal formations were apparent among these fetuses. Sensitivity for Down syn drome detection by ultrasound scans performed without knowledge of the fetal karyotype was 24.1 and 42.6 per cent before 13 weeks and betwee n 14 and 23 weeks, respectively. We conclude that structural abnormali ties are frequently observed in Down syndrome fetuses, but many sonogr aphic findings are not typically associated with this syndrome. (C) 19 97 by John Wiley & Sons, Ltd.