The objective of this study was to determine the rate, origin, maternal and perinatal outcomes, and the associated hospital costs of higher order multiple births in one Canadian province. All higher order multiple pregnancies (triplets and above) in Nova Scotia over a 22-year period (1980 to 2001) were reviewed, and the maternal and perinatal outcomes and hospital costs were compared with singletons and twins in the same hospital population. During the 22-year period, 116,785 infants were delivered, including 3448 twins, 99 triplets, and 16 quadruplets. Of the higher order multiple gestations, 51.4% were conceived through infertility therapy. When compared with mothers of either singletons or twins, mothers of higher order gestations were significantly older, had longer antepartum and postpartum hospital stays, were more likely to have cesarean delivery, preterm labor, preeclampsia, and require intensive care unit admission. Triplets and quadruplets had significantly higher rates of preterm delivery, major anomalies, neonatal intensive care, respiratory distress syndrome, intrauterine growth restriction, serious morbidity, 5-minute Apgar scores < or = 3, and neonatal death than twins or singletons. The estimated hospital costs for this population ranged from 6,750 US dollars for a singleton pregnancy to 278,400 US dollars for a quadruplet pregnancy. Maternal morbidity, perinatal morbidity and mortality, and hospital costs are significantly increased in higher order births compared with both twins and singletons.