Background Children with autism may experience increased head growth during the first year of life. Furthermore, early life exposure to endocrine disrupting chemicals (EDCs) may be associated with an increased risk of autism. Exposure to EDCs has been associated with fetal head circumference (HC), however research on long-term effects is scarce.
Objective To assess the association between prenatal exposure to various EDCs and HC in the first year of life.
Methods Cord plasma or breast milk was used to determine exposure to amongst others dichlorodiphenyldichloroethylene (DDE), mono (2-ethyl-5-hydroxyhexyl)phthalate (MEHHP), and mono (2-ethyl-5-carboxypentyl)phthalate (MECPP). Data on HC until 11 months after birth was obtained. Mixed models were composed for each compound. Exposure quartiles, time, and gender were added to the models as fixed effects. Subject was added as a random effect.
Results Boys with high MECPP exposure had a consistently higher HC than lower exposed boys (p = 0.047). This was also observed for girls in Q2 for both MEHHP (p = 0.018) and DDE (p < 0.001) exposure. For MEHHP the difference with the quartile showing the smallest HC was 2 cm at 11 months of age, which was not statistically significant (HC Q2: 44.9, 95% CI 43.2–46.7; HC Q3: 42.9, 95% CI 42.2–43.5).
Conclusion For MECPP, MEHHP, and DDE exposure over time, a higher HC was observed in low exposed children in a gender-specific way. Follow-up is warranted to see if associations persist into later childhood and are related to autism spectrum disorders.