The incidence of twin pregnancies has risen worldwide mainly because of the increase in the rates of assisted conception amongst other demographic and biologic factors. In the United States, there was an estimated increase of 76% between 1980 and 2009, from 18.9 to 33.3 per 1000 births. 1 Despite twins representing only 2 to 3% of live births, they account for 10 to 15% of the adverse neonatal outcomes. 2 Twin pregnancies, in comparison with singletons, are at an increased risk of complications including foetal anomalies, preterm birth, abnormal and discordant foetal growth, cerebral palsy, and perinatal and infant mortality. 3