The following is the summary of “Pregnancy-related factors may signal additional protection or risk of future cardiovascular diseases” published in the December 2022 issue of Women’s Health by Reddy, et al.

The Pooled Cohort Equation (PCE) is recommended by cardiovascular disease (CVD) guidelines for estimating 10-year CVD risk from traditional risk variables. Future cardiovascular disease has been linked to factors connected to pregnancy. By using the PCE, researchers analyzed the effect of two pregnancy-related factors on the risk of cardiovascular disease: a previous history of a low birthweight (LBW) infant and nursing. Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2006, a nationally representative sample of women aged 40-79 with a history of pregnancy but no prior CVD were found. The results were either death from cardiovascular disease or death from cardiovascular disease with surrogates. 

To account for the PCE risk score, investigators employed a Cox proportional hazards model. There were 479 LBW births and 1,926 breastfeeding mothers out of a total of 3,758 women. The average duration of the follow-up was 12.1 years. Breastfeeding has been shown to reduce the risk of cardiovascular disease in survival models. A 24% reduction in the risk of CVD deaths (HR 0.76; 95% CI 0.451.27, P=0.30) and a 33% reduction in the risk of CVD fatalities + surrogate CVD were observed in cause-specific survival models, although these results were not statistically significant. (HR 0.77; 95% CI 0.52─1.14, P=0.19). 

Confidence intervals were large in the survival models for LBW (cardiovascular disease death: HR 0.98; 95% CI 0.472.05, P=0.96; cardiovascular disease death plus surrogate CVD: HR 1.29; 95% CI 0.742.25; P=0.38). Potentially useful information about cardiovascular disease (CVD) risk beyond the usual suspects can be gleaned from pregnancy-related factors. Counseling women on the potential impact of pregnancy-related factors, especially the positive impact of breastfeeding, on cardiovascular health could be useful, while more study with larger datasets is needed.