Elective induction of labor as a risk factor for cesarean delivery among low-risk women at term

https://doi.org/10.1016/S0029-7844(00)00794-8Get rights and content

Abstract

Objective: To determine the effects of elective induction on the risk of cesarean delivery in a cohort of women with low-risk term pregnancies and to evaluate the costs of elective induction services within our hospital system.

Methods: Records of 1135 eligible women with low-risk, singleton, vertex pregnancies at 38–41 weeks’ gestation who were eligible for vaginal delivery were analyzed retrospectively after elective induction (n = 263) or spontaneous labor (n = 872). Outcome measures included cesarean delivery and direct costs. Variables evaluated were parity, maternal age, estimated gestational age, birth weight, prior cesarean delivery, epidural anesthetic use, and provider category. Analysis was by univariable and multivariable regression modeling.

Results: Elective induction placed nulliparas at a twofold higher risk for cesarean delivery (odds ratio 2.4, 95% confidence interval 1.2, 4.9) after adjustment for birth weight, maternal age, and gestational age. We found a significantly increased risk of cesarean delivery with increased birth weight for nulliparas (2–66.7%). Increasing maternal age increased the risk of cesarean delivery in all parity groups (P < .05), but particularly among nulliparas (3–26.3%) (P < .001). Electively induced labors that ended in vaginal delivery cost $273 more and required an average of 4 hours more in the hospital before delivery than did noninduced vaginal deliveries (P < .001).

Conclusion: Elective induction significantly increased the risk of cesarean delivery for nulliparas, and increased in-hospital predelivery time and costs.

Section snippets

Materials and methods

All 1810 women who delivered live-born infants and were discharged between June 1, 1997, and January 26, 1998, from St. Joseph’s Medical Center were identified through the hospital discharge data system. We excluded women with multiple gestations and women with gestations of less than 38 or at least 42 weeks. Women were considered ineligible for vaginal delivery if they had primary or secondary International Classification of Diseases, 9th Revision7 (ICD-9) codes of placenta previa or abruption

Results

Of 1135 eligible subjects, 263 (23.2%) underwent elective induction of labor. One hundred seventy inductions (64.6%) were done with up to three doses of oral misoprostol 50 μg, 70 (26.6%) were done by oxytocin infusion, 20 (7.6%) by artificial rupture of membranes only, and three (1.1%) with only prostaglandin (PG) gel. Eighty-two (48.2%) of 170 misoprostol inductions also involved oxytocin infusion, and three of those also included use of PG gel. Three (4.2%) of 70 oxytocin inductions also

Discussion

Despite suspected widespread use of elective induction, we found only ten published studies (MEDLINE search, 1970–1998, using the terms “labor,” “labour,” “induction,” “elective,” “techniques,” and “management”) involving more than 100 subjects that addressed elective induction and a variety of outcome measures since the advent of continuous fetal monitoring and controlled oxytocin infusion.10, 11, 12, 13, 14, 15, 16, 17, 18, 19 “Elective” was often defined in different ways, and consistency of

References (23)

  • T.M Eggebo et al.

    Labor induction. Quality assurance of a method [in Norwegian]

    Tidsskr Nor Laegeforen

    (1993)
  • Cited by (213)

    • The role of labor induction in modern obstetrics

      2024, American Journal of Obstetrics and Gynecology
    • Health resource utilization of labor induction versus expectant management

      2020, American Journal of Obstetrics and Gynecology
    View all citing articles on Scopus
    View full text