Background Breastfeeding is associated with improved cardiometabolic profiles decades after pregnancy. Whether this association exists for women who experience hypertensive disorders of pregnancy (HDP) is unknown. The authors examined whether breastfeeding duration or exclusivity are associated with long-term cardiometabolic health, and whether this relationship differs by HDP status. Methods and Results Participants (N=3598) were from the UK ALSPAC (Avon Longitudinal Study of Parents and Children) cohort. HDP status was assessed by medical record review. Breastfeeding behaviors were assessed by contemporaneous questionnaires. Breastfeeding duration was categorized as never, <1, 1 to <3, 3 to <6, 6 to <9, and 9+ months. Breastfeeding exclusivity was categorized as never, <1, 1 to <3, and 3 to 6 months. Measures of cardiometabolic health (body mass index, waist circumference, C-reactive protein, insulin, proinsulin, glucose, lipids, blood pressure, mean arterial pressure, carotid intima-media thickness, and arterial distensibility) were measured 18 years after pregnancy. Analyses were conducted using linear regression adjusting for relevant covariates. Breastfeeding was associated with improved cardiometabolic health (lower body mass index, waist circumference, C-reactive protein, triglycerides, insulin, and proinsulin) in all women, but not for every breastfeeding duration. Interaction tests revealed additional benefits in women with a history of HDP, with the strongest benefit observed in the 6- to 9-month breastfeeding category (diastolic blood pressure, -4.87 mm Hg [95% CI, -7.86 to -1.88], mean arterial pressure -4.61 [95% CI, -7.45 to -1.77], and low-density lipoprotein cholesterol, -0.40 mmol/L [95% CI, -0.62 to -0.17 mmol/L]). Differences in C-reactive protein and low-density lipoprotein "survived" Bonferroni correction (P<0.001). Similar results were observed in the exclusive breastfeeding analyses. Conclusions Breastfeeding may be a mechanism to reduce the cardiovascular disease sequela associated with HDP; however, there is a need to establish whether associations reflect a causal effect.
Keywords: breastfeeding; cardiometabolic health; cardiovascular disease; hypertensive disorders of pregnancy; preeclampsia.