PIP: The determinants and outcomes of unwanted pregnancies were explored in a prospective study of 1454 women who delivered in Moscow, Russia, during 1984-85. Mothers were interviewed during their postpartum hospital stay and again 3 years later. 131 women (9%) demonstrated a negative attitude toward their pregnancy. Another 72 women (5%) had a negative attitude initially, but developed positive feelings over the course of the pregnancy. The percentage of unwanted pregnancies was 2.9 times greater among unmarried women (14.9%) than married women (5.1%). Poor marital relationships, inadequate living conditions, tobacco/alcohol use, and low per capita income were found significantly more often among women with unwanted pregnancies. Significantly more infants of mothers with unwanted than wanted pregnancies had infants who were premature (28.3% vs. 9.5%) and low birth weight, but there was no significant difference in neonatal complications. Mothers of unwanted infants also were more likely to delay prenatal care and attend infrequently and, once the child was born, made fewer visits to the pediatrician. Even if unwanted pregnancy has no adverse medical sequelae, being unwanted should be considered a psychosocial risk factor with implications for a child's development.