A sophisticated regionalization plan in maternal and child care, including risk assessment, maternal transfer mechanisms, 24 hour communication availability, and regional tertiary perinatal intensive care units (high risk obstetrics integrated with level III neonatal intensive care), has allowed the Province of Ontario to significantly decrease perinatal mortality. Data collection by hospital of birth, birthweight and gestational age shows that this effect is most marked in the preterm infant between 25 and 32 weeks and in hospitals with small obstetrical volumes. Little decrease in incidence of preterm birth has occurred. Multiple births provide a significant number of the preterm births; singleton rates between 20-36 weeks are 5.48%, twins 42.97%, and triplets 95.3%. However, when compared with singletons of the same birthweight, the mortality rates for twins are less than those of singletons, and triplets are even less again. High incidence of prematurity in multiple pregnancies means that a regional perinatal unit has a large occurrence of maternally transferred high risk pregnancies. In our institute, a 10-year review between 1978 and 1988, showed an incidence of 24 triplet, four quadruplet, and one quintuplet pregnancies. Review of outcome and data relative to these pregnancies showed an early neonatal mortality rate of 31.6, a perinatal mortality rate of 51.5 and survival to discharge of 93%. The occurrence of neonatal complications was respiratory distress syndrome in 43%, bronchopulmonary dysplasia in 6%, and intraventricular hemorrhage in 4%. Long term follow-up showed only one severely handicapped child (mental retardation and cerebral palsy), 10 infants with a mild hypotonia and mild delay in gross motor development (both considered functional and transient), and 74% entirely normal. It is concluded that integrated perinatal care can result in excellent outcomes for multiple pregnancies as long as all components of antenatal, intrapartum, and neonatal care are combined effectively.