LAUSR

Objectives The goal of this study is to report the prevalence, aetiology and clinical outcome of pregnant women with heart failure. Methods This is a retrospective community-based cohort study that included pregnant women in the Kaiser Permanente Health System between 2003 and 2014. Women with heart failure were identified using International Classification of Disease, Ninth Revision codes. Medical records were manually reviewed to confirm diagnosis and adjudicate outcomes. Results In a cohort of 385 935 pregnancies, 488 (0.13%) had a diagnosis of heart failure, corresponding to 126 cases per 100 000 pregnancies. Peripartum cardiomyopathy was the most common cause of heart failure, accounting for 333 (68.2%) cases. Preterm birth and caesarean delivery were more common in patients with heart failure. Neonatal death rate was higher in the heart failure group (1.0% vs 0.4%, p=0.03). Infants delivered to women with heart failure had lower birth weights (3112.0±774.0 g vs 3331.9±575.5 g, p<0.001) and lower Apgar score at 1 min (7.9±1.5 vs 8.3±1.1, p<0.001). Median follow-up was 6.2 years (IQR 3.2–9.2). During follow-up, 7 (1.4%) in the heart failure group and 423 (0.11%) in the control group died. Heart failure was associated with a 7.7-fold increase risk of death (adjusted HR 7.7, 95% CI 3.6 to 16.4, p<0.001). Conclusion Heart failure during pregnancy is associated with unfavourable fetal outcomes including prematurity and low birth weight. While the overall mortality rate was low, pregnant women with heart failure carried an excess risk of death compared with controls.