Elective induction vs. spontaneous labor associations and outcomes.

OBJECTIVE

To determine factors and outcomes associated with elective medical induction of labor as compared with spontaneous labor in low-risk women.

STUDY DESIGN

Using a birth certificate database including 11,849 low-risk, laboring women, univariate and multiple logistic regression was used to evaluate demographic and obstetric factors associated with elective labor induction. Low risk was defined as singleton, vertex, 37-41 weeks' gestation, no prior cesarean section, and no presenting medical/obstetric diagnoses considered indications for cesarean or induction. Adverse neonatal outcome was defined as 1- or 5-minute Apgar score < 7, neonatal intensive care unit admission or respiratory distress. Spontaneously laboring women (n = 10,608) were compared with women who underwent induced labor for no apparent medical/obstetric reason (n = 1,241). Interventions and outcomes during and after labor induction were adjusted for relevant associated variables.

RESULTS

Odds ratios for epidural anesthesia, cesarean delivery and diagnoses of nonreassuring fetal heart rate patterns were independently increased following elective induction; odds ratios for cephalopelvic disproportion, instrumental delivery and adverse neonatal outcome were not. Maternal length of stay was 0.34 days longer with induction than with spontaneous labor (p < 0.0001). Slightly more induced labors ended before midnight.

CONCLUSION

As compared with spontaneous labor, elective labor induction is independently associated with more intrapartum interventions, more cesarean deliveries and longer maternal length of stay. Neonatal outcome is unaffected.