The purpose of the study was to develop a psychometrically reliable and valid instrument that assesses psychosocial factors that influence transition to motherhood in first-time pregnant adolescents 15-18 years of age. The descriptive, correlational study tested the Adolescent Prenatal Questionnaire (APQ) in 145 unmarried first-time pregnant adolescents 15-18 years of age who planned to keep their infants. Factor analysis yielded an interpretable four-factor solution that accounted for 40% of the variance with adequate internal consistency estimates and test-retest correlations to merit further testing.