Identification of monozygotic twins that are concordant for preeclampsia

Preeclampsia is thought to be discordant in monozygotic twins. While recruiting for a genetic study into preeclampsia, we identified 4 sets of twins and a triplet gestation; all were monozygous on deoxyribonucleic acid fingerprinting. Two twins were concordant for preeclampsia, and 2 of the triplets had pregnancy-induced hypertension, although only 1 of them had proteinuria. Hence we confirm the existence of monozygotic twins that are concordant for preeclampsia.