Characteristics and outcomes of pregnant women with cardiomyopathy stratified by etiologies: A population-based study.

Background: Heart failure is an uncommon diagnosis among pregnant women with limited data on this condition. We sought to describe the characteristics and outcomes of pregnant women with heart failure stratified by etiologies of cardiomyopathy.

Methods: This is a retrospective population-based cohort study across medical centers in Southern California in the United States. Pregnant women with heart failure were identified using ICD-9 codes and adjudicated by manual review of the medical records. Obstetric complications, fetal birthweight, and maternal mortality outcomes were evaluated.

Results: Between 2003 and 2014, there were 488 pregnancies (0.1% of all pregnancies) complicated by heart failure, of which 333 (68.2%) were due to peripartum cardiomyopathy (PPCM) and 155 (31.8%) were due to other etiologies (non-PPCM). Compared to patients with non-PPCM, patients with PPCM were more likely to be Black Americans (26.7% vs 15.5%) or Asian Americans (16.8% vs 7.1%). A high proportion of PPCM patients had preeclampsia (11.1% vs 5.2%, p = 0.04). Infants born to mothers with non-PPCM were more likely to be small for gestational age (SGA) (SGA <3% 4.1% vs 9.7%, p < 0.001; SGA <10% 20% vs 8.8%, p = 0.001). No significant difference in maternal mortality was observed between PPCM and non-PPCM patients.

Conclusions: PPCM is the most common etiology of HF during pregnancy. Infants born to mothers with PPCM were likely to be small for gestational age.