This chapter explores the maternal and fetal complications, advances in prenatal diagnosis, and management of complications unique to multiple gestations. Tidal volume and oxygen consumption in multiple gestations are increased, as is the normal alkalosis seen in singleton pregnancy. Hypertensive disorders increase by at least twofold in twin gestations. Hemorrhagic complications occur more frequently with twins. Growth of singletons and twins is comparable until 27 weeks gestation. The uterus accommodates the larger volume imposed by twins by overdistension, and beyond a certain limit, premature labor can result. Preterm deliveries (less than 37 weeks' gestation) occurred in 10.6% of singleton pregnancies against a phenomenal rate of 61.2% of live births in multiple gestations. Diagnosis of multiple gestations, establishing chorionicity, identifying anomalies, foreseeing possible maternal and fetal complications, prevention and treatment of preterm labor, and management of growth restriction are some of the areas of medicolegal concerns in multiple gestations.