Am J Perinatol 2019; 36(01): 045-052
DOI: 10.1055/s-0038-1648228
SMFM Fellowship Series Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Nonmedically Indicated Induction of Labor Compared with Expectant Management in Nulliparous Women Aged 35 Years or Older

Tetsuya Kawakita
1   Department of Obstetrics and Gynecology, MedStar Washington Hospital Center, Washington, District of Columbia
Katherine Bowers
2   Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
Jane C. Khoury
2   Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
3   Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
› Author Affiliations
Funding The data included in this article were obtained from the Consortium on Safe Labor, supported by the Intramural Research Program of the NICHD, NIH through contract number HHSN267200603425C. This project was funded in part with Federal funds (Grant # UL1TR000101 previously UL1RR031975) from the National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), through the Clinical and Translational Science Awards Program (CTSA), a trademark of DHHS, part of the Roadmap Initiative, “Re-Engineering the Clinical Research Enterprise.”
Further Information

Publication History

13 November 2017

22 March 2018

Publication Date:
03 May 2018 (online)


Objective This article compares maternal and neonatal outcomes in women aged ≥ 35 years who experienced nonmedically indicated induction of labor (NMII) versus expectant management.

Study Design This was a retrospective cohort study of nulliparas aged ≥ 35 years with a singleton and cephalic presentation who delivered at term. Outcomes were compared between women who underwent NMII at 37, 38, 39, and 40 weeks' gestation and those with expectant management that week. Adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) were calculated, controlling for predefined covariates.

Results Of 3,819 nulliparas aged ≥ 35 years, 1,409 (36.9%) women underwent NMII. Overall at 39 weeks' gestation or later, maternal and neonatal outcomes were similar or improved with NMII. At 37, 38, and 39 weeks' gestation, NMII compared with expectant management was associated with decreased odds of cesarean delivery at 37, 38, and 39 weeks' gestation. At 40 weeks' gestation, NMII compared with expectant management was associated with an increased odds of operative vaginal delivery and a decreased odds of neonatal intensive care unit (NICU) admission.

Conclusion In nulliparous women aged ≥ 35 years, NMII was associated with decreased odds of cesarean delivery at 37 to 39 weeks' gestation and decreased odds of NICU admission at 40 weeks' gestation compared with expectant management.


This study was approved by the MedStar Institutional Review Board (#2016–071, April 20, 2016). This study was presented as a poster presentation at the SMFM 37th Annual Meeting–The pregnancy meeting, Las Vegas, NV, January 23–28, 2017.

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