Objective: To evaluate monochorionic twins conceived by assisted reproductive technology (ART). Design: We compared perinatal outcomes of monochorionic twins conceived by ART with their dichorionic counterparts and with spontaneous monochorionic twins. Setting: Referral center. Patient(s): Mothers to monochorionic and dichorionic twins conceived by ART and spontaneous monochorionic twins. Intervention(s): None. Main Outcome Measure(s): Maternal characteristics, pregnancy complications, and perinatal outcomes. Result(s): Monochorionic twin pregnancies (n ¼ 25) comprise 7.2% of all ART twins and 4.9% of all monochorionic twins in this data set. Monochorionic pairs have a significantly worse outcome compared with dichorionic sets in terms of lower gestational age and birth weight. ART appears to increase the already high risk of monochorionicity compared with spontaneous conception: odds ratio (OR), 2.9 (1.1-7.3) for preterm birth at <32 weeks and OR, 5.9 (2.5-1.49) for birth weight <1,500 g.

Our data indicate that DC twins are not significantly disadvantaged compared to TC triplets and the similar outcomes might be reassuring for those who consider continuing their DC triplet pregnancy.

Twin pregnancies complicated by GDM might be associated with pre-pregnancy maternal obesity and are at increased risk of RDS and non-significant increased risk of perinatal death.

Todos os autores declaram não ter qualquer tipo de conflito de interesses relativamente ao presente manuscrito.