Long-term sequalae from hypertensive disorders of pregnancy (HDP) may be attenuated in part by breastfeeding, according to results of a study published in the Journal of the American Heart Association.
Data for this analysis were sourced from the Avon Longitudinal Study of Parents and Children (ALSPAC) which was a prospective population-based pregnancy cohort that recruited women and children in the United Kingdom (UK) between 1991 and 1992. In this analysis, responses to breastfeeding questionnaires administered at 6 and 15 months postpartum were associated with long-term cardiometabolic profiles at 18 years among a cohort of 3598 women. Hypertensive disorders of pregnancy were defined using the 2001 guidelines from the International Society for the Study of Hypertension in Pregnancy.
Patients were stratified by breastfeeding duration and the cohorts were women who never breastfed (n=509) or breastfed for less than 1 (n=317), 1 to 3 (n=428), 3 to 6 (n=653), 6 to 9 (n=651), or 9 (n=1040) or more months. The cohorts had mean ages of 28.2 to 31.3 years at delivery and 96.2% to 97.5% were White.
The trends in HDP differed significantly between cohorts (P =.001), in which the rates of gestational hypertension were highest among those who did not breastfeed (15.5%) and lowest among the patients that breastfed the longest (11.0%). Preeclampsia was highest among those who breastfed for 1 to 3 months (4.2%) and lowest for the patients that breastfed the longest (1.3%).
At 18-years follow-up, significant changes to C-reactive protein were positively related with duration of breastfeeding, from -17.12% for less than 1 month of breastfeeding to -25.50% for 6 to 9 months of breastfeeding. In general, breastfeeding for 6 to 9 months was associated with the greatest improvement in cardiometabolic health markers, specifically with improvements in body mass index (mean difference [MD], -0.55; P <.05), waist circumference (MD, -1.32 cm; P <.05), high-density lipoprotein cholesterol (MD, 0.07 mmol/L; P <.05), triglycerides (MD, -0.07 mmol/L; P <.05), insulin (MD, -10.59%; P <.05), and proinsulin (MD, -8.26%; P <.05).
Stratified by the presence of HDP, no significant changes in diastolic blood pressure, mean arterial pressure, low-density lipoprotein cholesterol (LDL-C), or glucose were observed at follow-up among those without HDP. For the HDP group, however, breastfeeding for 1 to 3 months was associated with improvements in mean arterial pressure (MD, -3.11; P <.05), LDL-C (MD, -0.41 mmol/L; P <.001), and glucose (MD, -4.78%; P <.05) whereas breastfeeding for 6 to 9 months was associated with improvements in diastolic blood pressure (MD, -4.87 mm Hg; P <.05), mean arterial pressure (MD, -4.61; P <.05) and LDL-C (MD, -0.40 mmol/L; P <.001).
In a sensitivity analysis which incorporated preterm birth, no significant differences in trends were observed. Similarly, accounting for parity did not affect trends.
These findings may be biased by the trends in pregnancy care and breastfeeding in the 1990s in the UK.
“Our results contribute to the evidence demonstrating that women with HDPs experience a similar or slightly enhanced cardioprotective benefit associated with breastfeeding as women who experienced a normotensive pregnancy,” the study authors wrote. “Because women who experience an HDP have excess risk of poor cardiometabolic health in the years following pregnancy, this high-risk group may derive the greatest benefit from breastfeeding should our results reflect a causal effect.”
Magnus MC, Wallace MK, Demirci JR, Catov JM, ÇSchmella MJ, Fraser A. Breastfeeding and later-life cardiometabolic health in women with and without hypertensive disorders of pregnancy. J Am Heart Assoc. Published online February 27, 2023. doi:10.1161/JAHA.122.026696