Gestational diabetes is associated with postpartum hemorrhage in Indigenous Australian women in the PANDORA study: A prospective cohort.

Abstract

OBJECTIVE: To assess associations of hyperglycemia in pregnancy with the risk of postpartum hemorrhage (PPH) in a prospective cohort of Indigenous and non-Indigenous women, compared to normoglycemia. METHODS: Data were from 1,102 (48% Indigenous) women of the Pregnancy And Neonatal Diabetes Outcomes in Remote Australia (PANDORA) Study. Age-adjusted associations of gestational diabetes mellitus (GDM) or pre-existing type 2 diabetes mellitus (T2DM), obstetric and demographic covariables with PPH (blood loss ≥500ml) were assessed using logistic regression. Multivariable-adjusted models included Indigenous ethnicity, diabetes type and their interaction. RESULTS: A higher proportion of Indigenous women developed PPH than non-Indigenous women (32% vs. 22%; p<0.001). Compared to non-Indigenous women with normoglycemia, risks of PPH for Indigenous women with GDM or T2DM were (OR=1.83 [95%CI: 1.11-3.02] and 1.72 [0.99-3.00] after age adjustment, 1.84 [1.06-3.19] and 1.33 [0.70-2.54] after adjustment for school education and delivery mode, and 1.62 [0.95-2.77] and 0.99 [0.53-1.86] after adjustment for birth weight). Importantly, Indigenous women without hyperglycemia in pregnancy were not at increased risk of PPH. CONCLUSION: The significantly higher rates of PPH experienced by Indigenous compared to non-Indigenous women may be explained by a greater effect of GDM among Indigenous women that was only partly accounted for by birth weight.