Are omphalocele and neural tube defects related congenital anomalies?: Data from 21 registries in Europe (EUROCAT).

We have analyzed the association between omphalocele and neural tube defects (O/NTD) previously reported in epidemiological studies of EUROCAT registry data [Dolk et al., 1991; Calzolari et al., 1995]. By examining differences in prevalence between the United Kingdom and Ireland (UKI) and Continental Europe and Malta (CEM) and differences in sex ratio, the possible etiopathogenetic differences between O/NTD association and omphalocele without NTD and NTD without omphalocele were investigated. The distribution of O/NTD cases according to NTD site in the two geographic areas shows in the UKI a tendency for omphalocele to associate with anencephaly/spina bifida and with anencephaly. In CEM centers, these types of NTD are much rarer. The pattern of other anomalies occurring in combination with O/NTD association in the same babies was also analysed.