This prospective study was undertaken to identify the significant risk factors associated with adverse pregnancy outcome in active-duty women. The deliveries of 300 consecutive pregnancies of active-duty women were assessed for maternal-fetal outcome. The risk factors evaluated were: marital status, parity, race, smoking and alcohol consumption while pregnant, maternal weight gain during pregnancy, maternal height, and educational level. Two-thirds of these women were junior enlisted personnel (rank E-4 or below) and worked under demanding job conditions over which they had little control. Increased age as a risk factor was associated with a significant increase in pregnancy-associated complications of cesarean birth, operative vaginal delivery, pregnancy-induced hypertension, preterm labor, maternal transport for fetal indications, intrauterine growth restriction, intrauterine fetal death, postpartum hemorrhage, placenta previa, and 5-minute Apgar scores <7 (p = 0.039). In gravidas more than 65 inches in height with a weight gain more than 42 pounds, there was a significant increase in the complications of pregnancy (p = 0.022). Interactions of these risk factors yielded a significant age (p = 0.025), maternal height (p = 0.007), and height times weight gain interaction (p = 0.006) association with pregnancy complications. The risk factors of advancing maternal age and tall stature with a maternal weight gain of more than 42 pounds are associated with increased pregnancy complications of active-duty women.