Advanced maternal age and postpartum hemorrhage – risk factor or red herring?

To determine the relationship between advanced maternal age (≥35 years) and incidence of postpartum hemorrhage (PPH) in singleton pregnancies managed over a 10-year period.Retrospective cohort study comparing demographics, risk factors, complications, infant outcome, and incidence of PPH between parturients aged ≥35 and35 years at delivery.Parturients aged ≥35 years (12 686/64 886 or 19.6%) had significantly increased obstetric risk factors, complications, cesarean delivery, large-for-gestational age infants, and incidence of PPH, but no difference in the attributed cause of PPH such as uterine atony, retained placenta, genital lacerations, except for multiple factors. Multivariate analysis indicated that aging was actually associated with decreased PPH, the risk decreasing progressively from those aged 25-29 years to those aged ≥40 years compared with the 20-24 years group.Advanced maternal age only served as a surrogate factor for PPH due to the associated increased risk factors, obstetric complications and interventions.