Objective The purpose of this study was to test the hypothesis that fatigue and sleep disturbance in late pregnancy are associated with labor duration and delivery type.

Study design In a prospective observational study of 131 women in their ninth month of pregnancy, objective (48-hour wrist actigraphy) and subjective (sleep logs and questionnaires) measures were used to predict labor outcomes using analysis of variance and logistic regression.

Results Controlling for infant birth weight, women who slept less than 6 hours at night had longer labors and were 4.5 times more likely to have cesarean deliveries. Women with severely disrupted sleep had longer labors and were 5.2 times more likely to have cesarean deliveries. Fatigue was unrelated to labor outcomes.