Outcome measures of obstetrical and perinatal care may concern the mother or the newborn and may involve mortality or morbidity. We reviewed the literature and found six outcome measures influenced by the process of care and its quality:maternal and perinatal mortalities, postpartum hemorrhage, sequelae of obstructed labor, Apgar scores and very early neonatal seizures. Birthweight and gestational age at delivery are additional variables to be taken into account as major confounding factors in inter-hospital or inter-area comparisons of mortality and morbidity. Other potentially useful outcome measures, such as the frequency of brachial-plexus palsy and of other birth injuries, need further study of their relation to the process of care before being recommended for routine use in quality assurance.