Hospitalization for cardiovascular disease in the year after delivery of twin pregnancies

Increased cardiovascular demand in twin pregnancies, even those without hypertensive disease of pregnancy (HDP), may pose a greater risk for cardiovascular complications compared with singletons. In this study, the risk of cardiovascular disease (CVD)-related hospitalizations and mortality within the year following delivery in relation to HDP was compared between twin and singleton pregnancies.

Using the Nationwide Readmissions Database of US hospitals from 2010 to 2020, the rates of CVD readmission in four exposure groups (twin deliveries with and without HDP and singleton deliveries with and without HDP) were estimated. Cox proportional hazard regression models were used to determine associations with singletons without HDP as the reference.

Of 36 million delivery hospitalizations, the rates of CVD readmission in twin and singleton pregnancies were 1105.4 and 734.1 per 100 000 delivery admissions, respectively. Compared with singletons without HDP, the adjusted hazard ratio (HR) of CVD readmission was highest for twins with HDP [HR 8.21, 95% confidence interval (CI) 7.48-9.01], followed by singletons with HDP (HR 5.89, 95% CI 5.70-6.08) and then twins without HDP (HR 1.95, 95% CI 1.75, 2.17).

Compared with singletons without HDP, twin pregnancies, even in the absence of HDP, are associated with increased risks for CVD complications in the first year post-partum. These findings highlight the increased strain twin pregnancies place on the maternal cardiovascular system. These findings advocate the need for appropriate pre-conception counselling for those with cardiovascular risk factors undergoing infertility treatment, which increase the risks of multi-foetal gestation, and increased post-partum surveillance in twin pregnancies.