Objective: The effect of the timing of admission in labor unit on the method of delivery was evaluated in a cohort study.
Method: Four hundred and sixty six low-risk nulliparous women who were admitted in the labor unit in latent phase (group 1) were compared with 329 parturient women who were admitted in the active phase (group 2) to determine rate of and reasons for cesarean section, cervical dilation at the time of cesarean, and the rate of labor augmentation.
Result: The number of cesarean deliveries in group 1 was greater than that in the group 2 (301 vs 80, p<0.0001 ). The main reason for cesarean section in group 1 was dystocia, and in 2, fetal distress. The rate of cesarean section in the women who were augmented was greater in group 1 than in group 2 (54% vs 23%, p<0.0001).
Conclusion: Later admission in labor increases the rate of spontaneous vaginal delivery in low risk nulliparous women.