Preterm induction of labor: predictors of vaginal delivery and labor curves

Maisa Feghali, Julia Timofeev, Chun Chih Huang, Rita Wesley Driggers, Menachem Miodovnik, Helain J. Landy, Jason G. Umans

Research output: Contribution to journalArticle


OBJECTIVE: The purpose of this study was to evaluate the labor curves of patients who undergo preterm induction of labor (IOL) and to assess possible predictors of vaginal delivery (VD).

STUDY DESIGN: Data from the National Institute of Child Health and Human Development Consortium on Safe Labor were analyzed. A total of 6555 women who underwent medically indicated IOL at

RESULTS: Rates of vaginal live births increased with GA, from 35% (group A) to 76% (group D). Parous women (odds ratio, 6.78; 95% confidence interval, 6.38-7.21) and those with a favorable cervix at the start of IOL (odds ratio, 2.35; 95% confidence interval, 2.23-2.48) were more likely to deliver vaginally. Analysis of labor curves in nulliparous women showed shorter duration of labor with increasing GA; the active phase of labor was, however, similar across all GAs.

CONCLUSION: Most women who undergo medically indicated preterm IOL between 24 and 36+6 weeks of gestation deliver vaginally. The strongest predictor of VD was parity. Preterm IOL had a limited influence on estimated labor curves across GAs.

Original languageEnglish (US)
JournalAmerican Journal of Obstetrics and Gynecology
Issue number1
Publication statusPublished - Jan 1 2015



  • induction of labor
  • labor curve
  • preterm

ASJC Scopus subject areas

  • Medicine(all)

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