Duration of Expulsive Efforts and Risk of Postpartum Hemorrhage in Nulliparous Women: A Population-Based Study

PLoS One. 2015 Nov 10;10(11):e0142171. doi: 10.1371/journal.pone.0142171. eCollection 2015.


Objective: To assess the specific association between the duration of expulsive efforts and the risk of postpartum hemorrhage.

Methods: Population-based cohort-nested case-control study of nulliparous women delivering vaginally in 106 French maternity units between December 2004 and November 2006, including 3,852 women with PPH (blood loss ≥ 500 mL and/or peripartum Hb decrease ≥ 2 g/dL), 1,048 of them severe (peripartum Hb decrease ≥ 4 g/dL or transfusion of ≥ 2 units of red blood cells), and 762 controls from a representative sample of deliveries without hemorrhage in the same population. The association between duration of expulsive efforts and postpartum hemorrhage was estimated by multilevel logistic regression models adjusted for individual and hospital characteristics.

Results: Median duration of expulsive efforts was 18 minutes among controls, 20 minutes among postpartum hemorrhage and 23 minutes among severe postpartum hemorrhage (p<0.01). Duration of expulsive efforts was significantly, positively, and linearly associated with both postpartum hemorrhage and severe postpartum hemorrhage. After adjustment for other risk factors, every additional 10 minutes of expulsive efforts was associated with about a 10% increase in the risk of postpartum hemorrhage (aOR = 1.11 [1.02-1.21]) and severe postpartum hemorrhage (aOR = 1.14 [1.03-1.27]). Oxytocin during labor, duration of active phase of labor, forceps use, episiotomy, perineal tears, and birth weight were also independently associated with both risks.

Conclusion: Duration of expulsive efforts was independently associated with postpartum hemorrhage and severe postpartum hemorrhage. Interventions to shorten the duration of this stage, such as oxytocin, forceps, and episiotomy, are also associated with higher risks of postpartum hemorrhage. Beyond duration, other aspects of the management of active second stage should be evaluated as some might allow it to last longer with a minimal increase in postpartum hemorrhage risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Delivery, Obstetric / adverse effects*
  • Female
  • Humans
  • Postpartum Hemorrhage / etiology*
  • Pregnancy
  • Risk Factors

Grants and funding

The PITHAGORE6 project was funded by the French Ministry of Health under its Clinical Research Hospital Program (contract no.27–35) and the Caisse Nationale d’Assurance Maladie (CNAMTS). Marie-Danielle Dionne was financially supported by the foundation of the Centre hospitalier universitaire de l’Université de Montréal (CHUM) and McGill University health centre (MUHC). These funders had no role in the design and conduct of the study, no role in the collection, analysis, or interpretation of the data, and no role in the writing of the manuscript or in the decision to submit for publication.