Clinical and Hematological Risk Factors for Postpartum Hemorrhage: A 2 Years Population Based Cohort Study in France

Objective: To determine clinical and hematological risk factors for immediate postpartum hemorrhage (PPH).

Design: A cohort study.

Setting: Obstetric unit of Brest University Hospital (France).

Population: All women who underwent a vaginal delivery between April 1, 2013 and May 29, 2015.

Methods: Clinical data were collected by obstetricians or midwives during antenatal care visits, labor and delivery, and recorded by trained research assistants in a standardized electronic case report form. Hematological variables, including immature platelet fraction, were measured from a blood sample systematically performed at the entrance in the delivery room.

Main Outcome Measures: Postpartum hemorrhage (PPH), measured with a graduated collector bag, was defined as blood loss of at least 500ml.

Results: 2742 women were studied. PPH occurred in 141 (5%) women. Seven clinical factors were independently associated with PPH: pre-eclampsia (OR 5.85, 95%CI 2.02-16.90), multiple pregnancy (OR 3.28 (1.21-8.91), assisted reproduction (OR 2.75, 95%CI 1.45-5.20), ante partum bleeding (OR 2.15, 95%CI 1.24-3.73), post-term delivery (OR 1.93, 95%CI 1.17-3.17), obesity (OR 2.95, 95%CI 1.76-4.93) and episiotomy (OR 2.51, 95%CI 1.63-3.74). Three hematological factors were additionally identified as potential predictive factors for PPH: platelets < 150 000 Giga/L (OR 2.98, 95%CI 1.63-5.46), fibrinogen < 4.5 g/dL (OR 1.86, 95%CI 1.21-2.87) and APTT ratio ≥ 1.1 (OR 2.16, 95%CI 1.31-3.57).

Conclusion: Besides classical risk factors, this study highlighted the role of assisted pregnancy and obesity in the PPH occurrence, and identified simple hematological predictive risk factors for PPH. How these parameters could be integrated in a helpful prediction score of PPH remains to be determined.