Discordant malformations in monochorionic twins: a retrospective cohort study in La Reunion Island.

Discordant malformation between monochorionic twins is a rare and unknown phenomenon. To estimate the incidence of discordant monochorionic twins and to describe their characteristics. A retrospective multicenter cohort of pregnancies between 2002 and 2015 in La Reunion Island was analyzed, thanks to a population-based register.