Objective Cardiovascular disease increases the risk of maternal mortality. This study examined the risk factors for cardiovascular events in pregnant women with cardiovascular disease. Methods This was a case-control study conducted in 2 phases at Japanese maternal and fetal care centers. The primary survey, using an interviewer-administered questionnaire, investigated whether the institutions had managed pregnant women with cardiovascular disease from April 2014 to March 2016. From 424 individual facilities surveyed, 135 facilities were found to have experience in managing pregnant women. In the secondary survey, the 135 institutions were asked to complete a web-based questionnaire, which collected detailed clinical information about cases, including cardiovascular disease, cardiovascular events, maternal background, and the perinatal outcome. Results Information on 302 pregnant women with cardiovascular disease was collected. None of the 302 patients died. There were 25 women with cardiovascular events (cardiovascular event group) and 277 women without cardiovascular events (non-cardiovascular event group); the two groups were compared. No significant differences were found in the perinatal outcomes. Medication use before pregnancy was identified as a risk factor for cardiovascular events (adjusted odds ratio, 23.28; 95% confidence interval, 8.15-66.47; p<0.001). In pregnant women with cardiovascular disease, New York Heart Association (NYHA) functional class II or III before pregnancy was associated with a higher risk of cardiovascular events in comparison to NYHA functional class I (p<0.001 for both). Conclusion Medication use before pregnancy and NYHA functional class >I were risk factors for cardiovascular events in pregnant women with cardiovascular disease.
Keywords: cardiovascular disease; cardiovascular event; maternal death; pregnancy.