Correlation between omphalocele contents and karyotypic abnormalities: sonographic study in 37 cases.

To evaluate the observation that fetuses with omphaloceles containing only bowel have an especially high prevalence of karyotypic abnormalities, we retrospectively reviewed the sonograms and case records of 37 fetuses with omphaloceles detected sonographically between 1984 and 1990. Nine fetuses had concomitant morphologic abnormalities characteristic of the amniotic band syndrome. Of the remaining 28 fetuses, karyotypic correlation was available in 22, and the karyotype was abnormal in five of these (23%). The omphaloceles contained liver in 22 fetuses and only bowel in six fetuses. Among fetuses with exteriorized liver, karyotypes were abnormal in one (6%) of 16 tested. In contrast, four (67%) of the six fetuses whose omphaloceles contained only bowel had abnormal karyotypes; for each of these four, sonograms showed morphologic abnormalities in addition to the omphalocele. In the two fetuses with bowel-only omphaloceles and normal karyotypes, the omphalocele was the only abnormality seen on sonograms, and these children are well after surgical repair. When fetuses with the amniotic band syndrome were excluded, sonograms showed concomitant anomalies in 15 fetuses with liver-containing omphaloceles, and the karyotype was abnormal in only one of these 15. The results of this study support previous observations that karyotypic abnormalities are more common in association with omphaloceles that contain only bowel compared with those that contain only liver. If we combine our data with data from three other studies that address this issue, 87% of fetuses with omphaloceles containing only bowel had an abnormal karyotype, a significantly higher rate than in those fetuses whose omphaloceles contained liver also (9%).