Prenatal exposure to polybrominated diphenyl ether (PBDE) and child neurodevelopment: The role of breastfeeding duration

Background: Prenatal and early-life exposure to polybrominated diphenyl ethers (PBDEs) is associated with detrimental and irreversible neurodevelopmental health outcomes during childhood. Breastfeeding may be a child's largest sustained exposure to PBDE- potentially exacerbating their risk for adverse neurodevelopment outcomes. However, breastfeeding has also been associated with positive neurodevelopment. Our study investigates if breastfeeding mitigates or exacerbates the known adverse effects of prenatal exposure to PBDEs and child neurodevelopment. Methods: Participants included 321 mother-infant dyads from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal birth cohort in California. PBDE concentrations were measured in maternal serum blood samples collected during pregnancy or at delivery. Using generalized estimated equations (GEE), we estimated associations of PBDE concentrations with children's attention, executive function, and cognitive scores assessed longitudinally between 7 and 12 years of age, stratified by duration of exclusive and complementary breastfeeding. Results: We observed that higher maternal prenatal PBDE concentrations were associated with poorer executive function among children who were complementary breastfed for a shorter duration compared to children breastfed for a longer duration; preservative errors (beta for 10-fold increase in complementary breastfeeding <7 months = -6.6; 95 % Confidence Interval (CI): -11.4, -1.8; beta >= 7 months = -5.1; 95 % CI: -10.2, 0.1) and global executive composition (beta for 10-fold increase <7 months = 4.3; 95 % CI: 0.4, 8.2; beta for 10-fold increase >= 7 months = 0.6; 95 % CI: -2.8, 3.9). Conclusions: Prolonged breastfeeding does not exacerbate but may mitigate some previously observed negative associations of prenatal PBDE exposure and child neurodevelopment.