The effect of breastfeeding on postpartum fructosamine and HbA1c values after normal pregnancy

Introduction: Breastfeeding can lower postpartum oral glucose tolerance test results by 5%. Similar data do not exist regarding fructosamine and HbA1c. The primary outcome was to determine if breastfeeding would lower fructosamine values by 5%. Methods: At the 4–8 week postpartum visit, women with uncomplicated pregnancies were given a questionnaire and had blood drawn for fructosamine and HbA1c. Results: Breastfeeding (n = 22) and non-breastfeeding women (n = 28) were demographically similar, including postpartum weight loss. The respective values among breastfeeding and non-breastfeeding women were: fructosamine 2.20 versus 2.21 mmol/L; HbA1c 5.2% versus 5.2%. Only two of the seven women with an HbA1c of 5.7% or more had an abnormal fructosamine. Conclusion: After uncomplicated pregnancies, breastfeeding was not associated with lower levels of postpartum fructosamine or HbA1c. Future research to improve screening for persistent postpartum dysglycemia in high-risk populations can utilize these tests without concern that results will be confounded by breastfeeding.