A comparison of maternal and perinatal outcomes with vaginal delivery: indicated induction versus spontaneous labor.

Objective: To determine if there is a difference in the maternal and perinatal characteristics and outcomes of women undergoing a medically indicated labor induction and delivering vaginally compared to women in spontaneous labor delivering vaginally.Methods: This is a planned secondary analysis of previously published data with additional data collected for a case-control design. Maternal and perinatal characteristics and outcomes of women undergoing a medically indicated labor induction of labor and delivering vaginally were compared with the next woman who went into labor spontaneously and delivered vaginally.Results: There were 1097 women in the medically indicated labor group and 1096 women in the spontaneous labor group. The medically indicated induction group was younger (p < .0001), had less women of "other" race (p = .004), were of a lower gravidity and parity (p < .0001), had a lower Bishops' score on admission (p < .0001), had a greater proportion of umbilical arterial cord pH values <7.1 and <7.0 (p < .0001). Additionally, the induction group had longer first and second stages of labor (p < .0001). While the unadjusted rates of post-partum complications and NICU admission were higher in the medically indicated labor induction group, only cord gas pH <7.1 remained statistically significant after adjustment.Conclusion: Even with successful vaginal delivery of a medically indicated induction of labor, the risk for adverse outcomes remains elevated.