Introduction: Hypertensive disorders of pregnancy (HDP) occur in approximately 7-10% of pregnancies and are a leading cause of perinatal morbidity and mortality for both mother and child. Further, HDP has been shown to increase the mother’s long-term risk of developing cardio-metabolic diseases. In contrast, breastfeeding is thought to protect against hypertension and diabetes in a time- and dose-dependent manner. Our study aimed to examine the relationship between HDP and breastfeeding outcomes in the first year after delivery.
Methods: We conducted a secondary analysis of data from the All Our Families (AOF) prospective pregnancy cohort from Calgary, Alberta, which contains questionnaire and linked electronic medical record data. We included all women with complete data on the questionnaires completed at 36 weeks’ gestation, and at four and 12 months postpartum. We examined associations between HDP, breastfeeding initiation, duration, and exclusivity, using Chi-Square and regression analyses, controlling for confounders as appropriate.
Results: Participants (N=1418) were primarily white, well-educated, primiparous, and married. The incidence of HDP was 8.6% (n=122). Chi-square analyses showed that there was no difference in breastfeeding initiation and continuation rates; however, logistic regression analysis showed that women with HDP had a significant increase in odds of non-exclusive (vs. exclusive) breastfeeding at four months postpartum, OR=2.47, 95% CI (1.62, 3.80), relative to their unaffected counterparts (Table 1). Further, multiple linear regression showed that women with HDP reported breastfeeding for 6.3 weeks less than those without, b=-6.34, SE=1.86, p<.001 (Table 2).
Conclusion: Women with HDP tend to breastfeed non-exclusively and for a shorter duration than other mothers. This is particularly concerning given that HDP is an independent risk factor for future cardio-metabolic disorders. Given the potentially central role of lactation in mitigating such adverse outcomes, further research on the physiological, mechanical, and psychological barriers to prolonged, exclusive breastfeeding in this at-risk population is warranted.
Katie Chaput– Assistant Professor, Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB
Tuong-Vi Nguyen Nguyen– Assistant Professor, McGill University Health Center
Lianne Tomfohr-Madsen– Associate Professor, University of Calgary
Natalie Dayan– Assistant Professor, McGill University Health Center
Deborah Da Costa– Associate Professor, McGill University Health Center
Suzanne Tough– Professor, Department of Paediatrics, University of Calgary, Calgary, AB