The effect of the contents of exomphalos and nuchal translucency at 11-14 weeks on the likelihood of associated chromosomal abnormality

OBJECTIVES: Previous publications suggest that exomphalos containing the liver as less likely to be associated with aneuploidy. The objective of the study was to explore the influence of exomphalos contents and nuchal translucency (NT) on the likelihood of aneuploidy. METHODS: A retrospective search was conducted to identify all cases of exomphalos from the databases of two fetal medicine units seen from September 2000 to March 2011. RESULTS: A total of 95 fetuses with exomphalos were selected. NT was normal in 42 fetuses (44.2%). The exomphalos content was bowel alone in 68 (71.6%). The effect of exomphalos content and NT on likelihood of aneuploidy was explored using logistic regression. It showed no significant contribution of exomphalos content on the likelihood of aneuploidy (adjusted odds ratio: 1.44, 95% CI: 0.538 to 3.84). CONCLUSIONS: When the diagnosis is made in the first trimester, the risk of aneuploidy is no different when the sac contains only bowel as compared with when it contains the liver. Increase in the NT is 4-5 times as likely with an abnormal karyotype as with normal NT. Detection of exomphalos in the first trimester warrants an offer of chromosomal assessment regardless of sac contents or NT.