Prenatal Exposure to Perfluoroalkyl Substances and Dysmorphic Facial Features at age 5

Abstract

Background: Perfluoroalkyl substances (PFAS) are widespread persistent pollutants suggested to induce developmental neurotoxicity in animals, but evidence from human studies remains inconclusive. Epidemiological studies have focused on neurobehavioral and psychological evaluations but other measures such as facial features anomalies have never been investigated. Facial dysmorphia is known to accompany impaired development in the central nervous system and part of the diagnosis of the Fetal Alcohol Syndrome. Objective: To investigate the association between prenatal PFAS exposures and facial features measured at age 5. Methods: We analyzed standardized digital facial photographs taken from 670 children enrolled in the Danish National Birth Cohort (DNBC) at age 5 and three facial features (palpebral fissure length (PFL), philtrum groove, and upper lip thickness) using the Facial Photographic Analysis Software. The features were classified as short or normal PFL as binary outcomes, while philtrum (grooved or smooth versus normal) and upper lip (thick or thin versus normal) were classified in three groups. Six types of prenatal PFAS in maternal plasma collected in early pregnancy (median, 8 gestational weeks) were studied. We conducted logistic regression analysis and estimated the odds ratio (OR) and 95% confidence interval (CI) for each facial feature using the normal group as the reference according to log2-PFAS level (ng/mL), adjusting for potential confounders including maternal alcohol intake, smoking and age. Results: We found that all six types of prenatal PFAS levels were correlated with higher odds for having a short PFL (e.g. OR ranging from 1.38 to 2.23) with the association being the strongest for perfluorodecanoic acid (PFDA, OR: 2.23, 95% CI: 1.21, 4.11). There were no associations between any of the PFAS and philtrum smoothness or upper lip thickness. Conclusion: Maternal pregnancy PFAS serum levels were associated with shorter PFL in the offspring. Our findings are novel and warrant further research.