With increasing numbers of women delaying child-bearing past the age of 30, it becomes important to determine if such shifts in childbearing patterns are reflected in higher maternal and neonatal perinatal morbidity. To assess this issue, the authors evaluated 3917 consecutive primiparous women, 20 years or older, delivering a singleton infant for the period 1985–1987. Data were derived from computerized data-adapted forms. Information gathered included rates of low-birth-weight, pre-term and small-for-gestational-age deliveries, fetal mortality in fetuses weighing 500 g or more, antepartum and intrapartum complications, cesarean delivery rates, frequency of low Apgar scores, need for NICU admission, and the relationship between age and such covariates as race, education, smoking and chronic medical conditions (hypertension, diabetes).