Increasing trends in atonic postpartum haemorrhage in Ireland: an 11-year population-based cohort study

Abstract

Objective: To derive nationally representative incidence rates of postpartum haemorrhage (PPH), and to investigate trends associated with method of delivery, blood transfusion and morbidly adherent placenta (accreta, percreta and increta).

Design: Population-based retrospective cohort study.

Setting: Republic of Ireland.

Population: Childbirth hospitalisations during the period 1999-2009.

Methods: International Classification of Diseases (ICD)-9-CM and ICD-10-AM diagnostic codes from hospital discharge records were used to identify cases of PPH. Significant temporal trends in PPH incidence were determined using Cochrane-Armitage tests for trend. Log-binomial regression was conducted to assess annual changes in the risk of PPH diagnosis, with adjustment for potential confounding factors.

Main outcome measures: PPH, uterine atony, blood transfusion and morbidly adherent placenta.

Results: A total of 649,019 childbirth hospitalisations were recorded; 2.6% (n = 16,909) included a diagnosis of PPH. The overall PPH rate increased from 1.5% in 1999 to 4.1% in 2009; atonic PPH rose from 1.0% in 1999 to 3.4% in 2009. Significant increasing trends in atonic PPH rates were observed across vaginal, instrumental, and emergency and elective caesarean deliveries (P < 0.001). The rate of atonic PPH co-diagnosed with blood transfusion also significantly increased (P < 0.001). Relative to 1999, the risk of atonic PPH in 2009 was three-fold increased (adjusted RR 3.03; 95% CI 2.76-3.34). Women diagnosed with a morbidly adherent placenta had a markedly higher risk of total PPH (unadjusted RR 13.14; 95% CI 11.43-15.11).

Conclusions: Increasing rates of atonic PPH highlight the pressing need for research and for clinical audit focusing on aetiological factors, preventative measures and quality of care, to guide current clinical practice.