Increased prevalence of postpartum haemorrhage in pregnancies resulting from oocyte donation compared with IVF, or natural conception: a systematic review and meta-analysis

Oocyte donation (OD) enables an increasing number of women to conceive.However, OD pregnancies have a high risk for pregnancy complications, such as severe postpartum hemorrhage (PPH).To provide an overview of current existing knowledge on the risk of developing PPH in OD pregnancies, and its possible pathophysiology, we conducted a systematic review and meta-analysis.A systematic search in PubMed and Embase databases was conducted to retrieve observational studies that compared OD pregnancies with autologous oocyte in vitro fertilization (AO-IVF), or naturally conceived (NC) pregnancies, reporting on PPH as one of the outcome measures.The literature search yielded eighteen eligible studies for the systematic review; seventeen were included in the meta-analysis.The meta-analysis showed an overall significant risk of PPH in OD versus AO-IVF/ICSI pregnancies ) and NC pregnancies (OR 3.15 [95% CI 2.01-4.94]),although heterogeneity was present.All sub-analyses using different definitions of PPH as well as sensitivity analyses for adjusted ORs and low risk of bias showed similar result.This systematic review and meta-analysis confirms and provides more robust evidence compared to previous meta-the increased risk of PPH in OD pregnancies when compared with both NC pregnancies and AO-IVF/ICSI pregnancies.