The twin incidence is higher in infants with oesophageal atresia (OA) than
in the general population. The purpose of this study was to review the twin
OA information from five institutions and evaluate possible links between
the development of OA and the twinning process. Data were compared, combine
d, and analysed. There was a total of 1215 infants with OA, of whom 50 were
from a twin pregnancy and 1 from a triplet pregnancy. Two sets of twins we
re concordant for OA. Mean birth weights and gestational ages were lower in
the twin infants (P < 0.0005) and survival was lower in twins (65%, P < 0.
005) than singletons. The anatomical variant of pure OA without fistula was
seen in proportionally fewer twins (4%) than in singletons 1(7%). Multiple
anomalies were present in 40% of twins compared with 33% of singletons, al
though this did not reach statistical significance. OA in our multicentre p
opulation was more common in twins. Several possible mechanisms are put for
ward to explain the apparent link between twinning and OA. Further analysis
of this aspect of OA may aid in understanding the aetiology of this congen
ital anomaly.