The association between ragged or incomplete membranes and postpartum haemorrhage: A retrospective cohort study.

ABSTRACT

BACKGROUND: The association between an incomplete placenta and postpartum haemorrhage (PPH) is well documented; however, the significance of ragged or incomplete membranes has not been explored as an independent risk factor for PPH. AIMS: To explore the association between the completeness of the amniotic and chorionic membranes and the risk of PPH, independent to placental status. MATERIALS AND METHODS: 37 176 birth records were retrospectively extracted from the period 1 July, 2008 to 30 June, 2016 from the databases of two public hospitals in Melbourne, Australia. Following application of specific exclusion and inclusion criteria, including non-complete placentas, 5718 records were available for analysis. These records were grouped based on membrane status (complete, ragged or incomplete) and outcome (PPH or no PPH). RESULTS: Primary PPH rates were 14.8% in women with complete membranes, 20.2% in women with ragged membranes and 25.8% in women with incomplete membranes. Following statistical adjustment, the risk ratios for PPH were 1.32 (95% CI 1.15-1.50) and 1.70 (95% CI 1.41-2.04) in women with ragged and incomplete membranes, respectively. CONCLUSIONS: Both ragged and incomplete membranes were found to be independent risk factors for primary PPH. This previously un-discussed association has the potential to influence clinical practice changes, particularly with regard to the ongoing clinical relevance and use of the terms 'ragged' and 'incomplete' membranes.