Trends, causes and factors associated with primary Postpartum Haemorrhage (PPH) in Ireland: A review of one million hospital childbirths

Objective: To analyse temporal trends for primary Postpartum Haemorrhage (PPH), Major Obstetric Haemorrhage (MOH) between 2005 and 2021 and to examine the causes and factors contributing to the risk of PPH during 2017–2021. Methods: International ICD-10-AM diagnostic codes from hospital discharge records were used to identify cases of PPH. Temporal trends in PPH and MOH incidence were illustrated graphically. Poisson regression was used to assess the time trends and to examine factors associated with the risk of PPH during 2017–2021. Results: A total of 1,003,799 childbirth hospitalisations were recorded; 5.6% included a diagnosis of primary PPH. Risk increased almost fourfold from 2.5% in 2005 to 9.6% in 2021. The ICD-10 AM code for other immediate primary PPH was recorded for 85% of PPH cases in 2017–2021 whereas a diagnosis of uterine inertia/atony was associated with just 3.6% of the cases. Respectively, trauma-related, tissue-related and thrombin-related causes were associated with one third, 4.2% and 0.5% of cases. A wide range of factors relating to the woman including comorbidities, mode of delivery, labour-related interventions and associated traumas increased risk of PPH but placental complications, especially morbidly adherent placenta, were strong risk factors. Conclusions: Improvement in detection and anticipation of placental complications may be effective in addressing the increasing trend of PPH, however, the trends of increasing C-sections and other interventions may also need to be addressed while staff education and quality improvement projects will have a role to play.