Durations of second stage of labor and pushing, and adverse neonatal outcomes: a population-based cohort study

J Perinatol. 2017 Mar;37(3):236-242. doi: 10.1038/jp.2016.214. Epub 2016 Dec 8.


Objective: The associations between duration of second stage of labor, pushing time and risk of adverse neonatal outcomes are not fully established. Therefore, we aimed to examine such relationships.

Study design: A population-based cohort study including 42 539 nulliparous women with singleton infants born in cephalic presentation at ⩾37 gestational weeks, using the Stockholm-Gotland Obstetric Cohort, Sweden, and the Swedish Neonatal Quality Register, 2008 to 2013. Poisson regression was used to analyze estimated adjusted relative risks (RRs), with 95% confidence intervals (CIs). Outcome measures were umbilical artery acidosis (pH <7.05 and base excess <-12), birth asphyxia-related complications (including any of the following conditions: hypoxic ischemic encephalopathy, hypothermia treatment, neonatal seizures, meconium aspiration syndrome or advanced resuscitation after birth) and admission to neonatal intensive care unit (NICU).

Results: Overall rates of umbilical artery acidosis, birth asphyxia-related complications and admission to NICU were 1.08, 0.63 and 6.42%, respectively. Rate of birth asphyxia-related complications gradually increased with duration of second stage: from 0.42% at <1 h to 1.29% at ≥4 h (adjusted RR 2.46 (95% CI 1.66 to 3.66)). For admission to NICU, corresponding rates were 4.97 and 9.45%, and adjusted RR (95% CI) was 1.80 (95% CI 1.58 to 2.04). Compared with duration of pushing <15 min, a duration of pushing ⩾60 min increased rates of acidosis from 0.57 to 1.69% (adjusted RR 2.55 (95% CI 1.51 to 4.30)).

Conclusion: Prolonged durations of second stage of labor and pushing are associated with increased RRs of adverse neonatal outcomes. Clinical assessment of fetal well-being is essential when durations of second stage and pushing increases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acidosis / epidemiology*
  • Adult
  • Asphyxia Neonatorum / epidemiology*
  • Cohort Studies
  • Databases, Factual
  • Delivery, Obstetric / methods
  • Female
  • Humans
  • Infant, Newborn
  • Intensive Care Units, Neonatal / organization & administration
  • Labor Stage, Second / physiology*
  • Obstetric Labor Complications / epidemiology*
  • Patient Admission
  • Pregnancy
  • Pregnancy Outcome*
  • Pressure / adverse effects
  • Regression Analysis
  • Risk Factors
  • Sweden
  • Time Factors
  • Uterine Contraction
  • Young Adult