Aims Exomphalos occur in one in 4000 live births, affected infants suffer significant mortality and morbidity. The aim of this study was to quantify those adverse outcomes, in particular to determine the impact of the size of the exomphalos.

Methods Analysis was undertaken of all live-born infants with an antenatal diagnosis of exomphalos born between 2004 and 2015. Comparison was made of the results of those with exomphalos major (defined as a defect containing both bowel and liver) and those with exomphalos minor (defined as a defect containing only bowel).

Results Outcomes from 27 infants with major and 23 with minor exomphalos were compared. There were no significant differences in the gestational age at birth or the birth weight of those with a major or minor exomphalos. Infants with a major exomphalos had a greater mortality (26% vs. 0%), p = 0.002)and more morbidity: a longer length of ventilation (median 13.5 vs. 2 days), p = 0.001, a greater need for high frequency oscillation (30% vs. 0%) p = 0.005, a longer duration of supplementary oxygen (median 23 vs. 1 day), p < 0.001, more were oxygen dependent at 28 days (BPD) (33% vs. 9%), p = 0.03, a longer time to commence enteral feeds (median 8 vs. 5 days), p = 0.004 and a longer length of stay (median 16 vs. 14 days), p = 0.001. Infants who died had a lower birth weight (p = 0.007), a lower gestational age (p = 0.012), a longer length of ventilation (p = 0.003), a greater need for HFOV (p < 0.0001) and nitric oxide (p < 0.001) and more had BPD (p = 0.034).

Conclusions Infants with giant exomphalos suffer greater mortality and morbidity than those with minor defects, these results are important to inform antenatal counselling of prospective parents.