Objective: To calculate the incidence of jejunal atresia in newborns in The Netherlands. To study the relation between the occurrence of jejunal atresia and genetic amniocentesis to determine a possible iatrogenic cause for the unexpected high incidence of this anomaly in twins.
Design: Retrospective study.
Subjects: Eighty-nine consecutive twin pregnancies in which amniocentesis had been performed for prenatal diagnosis. In 86 methylene blue solution had been used to mark the amniotic cavity that was punctured first.
Main outcome measure: The occurrence of jejunal atresia in one of the two twin infants.
Results: The incidence of jejunal atresia at birth in The Netherlands is estimated to be 1 in 14,000. This anomaly occurred in 17 out of 89 twin pregnancies (19%). In 15 of the 17 it was possible to determine which of the two children had been exposed to intra-amniotic methylene blue. In all 15 pregnancies, the infant exposed to the dye was suffering from jejunal atresia.
Conclusion: A causal relation between the use of methylene blue in second trimester amniocentesis and the occurrence of jejunal atresia is strongly suggested. We recommend that no dyes should be injected into the amniotic sac.