Risk factors for maternal cardiac and obstetric outcomes in patients with and without CHD.

Background: Physiologic changes in the peripartum period put women with CHD at increased risk for morbidity. This study examines factors associated with peripartum complications and length of stay compared to patients without CHD.

Methods: This single-institution retrospective case-control study included women with CHD (2000-2017) and a control population without CHD. A review of clinical and echocardiographic data was used to assign baseline characteristics, disease severity, and adverse outcomes. Primary outcomes were composite variables of cardiac and obstetric adverse events, along with peripartum length of stay. The relationship between maternal CHD, baseline characteristics, and peripartum adverse events was evaluated by multivariable regression.

Results: The cohort and control groups included 162 deliveries among 113 women and 321 deliveries among 321 women, respectively. Cardiac complications, including arrhythmia, heart failure, pulmonary oedema, and thromboembolic events, occurred in 8.6% of the cohort (RR 2.52, 95% CI 1.17-5.42), with the most common event being arrhythmia. Obstetric events, such as caesarean delivery, assisted vaginal delivery, preterm birth, and pre-eclampsia, occurred in 67.9% versus 56.1% in the control group (RR 1.21, 95% CI 1.05-1.40). In multivariable models, increasing age was associated with increased composite cardiac events. Length of stay was longer in the cohort group (p < 0.001) and significantly associated with modified World Health Organization classification (p = 0.016).

Conclusions: Women with CHD experience increased cardiac and obstetric morbidity compared to controls during peripartum admission. Those with CHD have longer hospital stays around delivery, which is associated with disease severity.