Introduction: Hypertensive disorders of pregnancy (HDP) are independent risk factors for premature coronary artery disease (CAD). While breastfeeding is known to reduce long-term CAD risk, its effects on immediate postpartum cardiometabolic health are not fully understood. The aim of this study is to assess the effect of breastfeeding on cardiovascular risk factors in early postpartum following a HDP.
Methods: This registry analysis included 61 women with HDP requiring pharmacotherapy, attending a postpartum cardiovascular preventative clinic at a tertiary hospital in Adelaide, South Australia. Patients completed a self-reported breastfeeding questionnaire. Breastfeeding frequency at approximately 6 months postpartum was assessed using a lactation intensity ratio, measuring the proportion of breastfeeds per day (including expressing breastmilk) in relation to other forms of feeding.
Results: At 6 months postpartum, 42% of women reported low lactation intensity (<20% breastfeeding). Women with a high lactation intensity (>80% breastfeeding) had significantly lower mean systolic blood pressure (120.4mmHg±9.6 vs. 132.2mmHg±14.1), diastolic blood pressure (74.6mmHg±9.0 vs. 81.9mmHg±9.2), central systolic (113.5mmHg ±10.9 vs. 124.4 mmH±11.4) and diastolic blood pressure (76.1mmHg±9.4 vs. 85.3 mmHg±13.4) than women with low lactation intensity. They also reported higher HDL cholesterol (1.6mmol/L±0.3 vs. 1.3mmol/L±0.3) and lower serum insulin levels (10.1mg/dL±5.5 vs 18.5mg/dL±11.7).
Conclusion: Women with a previous HDP who had higher lactation intensity had improved cardiometabolic health compared to those with low lactation intensity. Breastfeeding should be encouraged for women with a previous HDP to reduce future cardiovascular risk. Further research is required to address the psychosocial and physical barriers to breastfeeding in this high-risk cohort.