Recent research focuses on hypertensive disorders in pregnant and postpartum women, investigating the risk of cardiovascular disease-related readmission in patients with eclampsia and the association between hypertensive disorders of pregnancy and breastfeeding. These studies were published in the European Heart Journal and JAMA Network Open, respectively.

Jessica C. Fields, MD, et al., looked at more than 27 million delivery hospitalizations captured by the Nationwide Readmissions Database from 2010 to 2018, 20,478 of which had reported eclampsia complications. Their analysis explored associations between eclampsia and rehospitalization due to cardiovascular disease within one year after delivery.

Comparing eclampsia vs. normotensive patients, cardiovascular disease readmission rates were 854 vs. 147 per 100,000 delivery hospitalizations, respectively, resulting in a hazard ratio (HR) of 6.9 (95% CI 4.5-10.4).

Certain heart disease subtypes exhibited a substantially higher risk for readmission. The highest risk among patients with eclampsia was for hypertensive heart disease (HR 15.5, 95% CI 7.9-30.2) and heart failure (HR 7.6, 95% CI 4.7-12.5). Eclampsia was also significantly associated with high risk for stroke readmission (adjusted HR 12.6, 95% CI 6.9-22.8).

"The extremely high stroke rate in postpartum eclampsia highlights the increased risk for stroke morbidity postpartum," state the authors. "However, it should be noted that the study is underpowered by stratification of the exposure to antepartum, at birth, and postpartum eclampsia, and it may be challenging to interpret these results fully."

An additional study by Deanna Nardella, MD, MHS, et al., incorporates nationally representative data from the Centers for Disease Control and Prevention Pregnancy Risk Assessment Monitoring System. They included 205,247 postpartum women (representative of >10 million women, mean age 30 years, 99% first-time mothers). Overall, 17% of women reported hypertensive disorders of pregnancy and 88% reported starting breastfeeding.

Main outcomes analyzed were odds of never breastfeeding, hazard of breastfeeding cessation and median time to breastfeeding cessation. After adjustment for sociodemographic and maternal-infant health factors, hypertensive disorders of pregnancy was associated with greater odds of never breastfeeding (adjusted odds ratio, 1.11; 95% CI, 1.05-1.18).

Additionally, postpartum women with a hypertensive disorder who reported starting to breastfeed had a higher adjusted hazard of breastfeeding cessation (adjusted HR, 1.17; 95% CI, 1.14-1.21). Those with hypertensive disorders of pregnancy exhibited a median breastfeeding duration of 17 weeks (IQR, 5 to >47), while the median for those without was 34 weeks (IQR, 9 to >47).

"These findings cause concern, as breastfeeding duration directly relates to the degree of cardiometabolic benefit for the lactating woman," write the authors. "The duration of breastfeeding necessary to maximize maternal cardiovascular benefit is not clear."