Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

Am J Obstet Gynecol. 2009 Oct;201(4):357.e1-7. doi: 10.1016/j.ajog.2009.08.003.


Objective: The purpose of this study was to assess maternal and perinatal outcomes as a function of second-stage labor duration.

Study design: We assessed outcomes in nulliparous laboring women who were enrolled in a trial of fetal pulse oximetry.

Results: Of 5341 participants, 4126 women reached the second stage of labor. As the duration of the second stage increased, spontaneous vaginal delivery rates declined, from 85% when the duration was <1 hour to 9% when it was > or =5 hours. Adverse maternal outcomes that were associated significantly with the duration of the second stage of labor included chorioamnionitis (overall rate, 3.9%), third- or fourth-degree perineal laceration (overall rate, 8.7%), and uterine atony (overall rate, 3.9%). Odds ratios for each additional hour of the second stage of labor ranged from 1.3-1.8. Among individual adverse neonatal outcomes, only admission to a neonatal intensive care unit was associated significantly with second stage duration (odds ratio, 1.4).

Conclusion: The second stage of labor does not need to be terminated for duration alone.

Publication types

  • Comment
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Birth Injuries / epidemiology
  • Brachial Plexus / injuries
  • Female
  • Humans
  • Intensive Care Units, Neonatal
  • Labor Stage, Second*
  • Parity
  • Pregnancy
  • Pregnancy Outcome*
  • Risk Factors
  • Time Factors

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