Associations between in utero phthalate exposure and non-nutritive suck

Abstract

TPS 731: Neurological effects in children, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Infant non-nutritive suck (NNS), or sucking on a pacifier with no nutrient being delivered, has been linked to childhood language, motor, IQ and overall neurodevelopment and is considered an index of early brain development. However, it remains unknown if an infant’s NNS pattern is a sensitive indicator of neurotoxicity induced by exposure to environmental contaminants. Our aim was to examine associations between in utero exposure to phthalates, chemicals widely used in plastics and personal care products, and infant NNS. Methods: The Center for Research on Early Childhood Exposure and Development (CRECE) examines how environmental exposures impact the health and development of infants and children living on the heavily-contaminated island of Puerto Rico. In this ongoing birth cohort, we measure maternal urinary concentrations of phthalate metabolites throughout pregnancy as measures of intrauterine exposure to their child. NNS is then measured in infants at 4-6 weeks of age using a custom research pacifier, yielding NNS amplitude (CmH20), frequency, bursts/min, cycles/min, and cycles/burst. Results: Thus far, we have NNS and in utero phthalate measures on 88 full-term infants (47 males) in this ongoing study. Linear models, controlling for sex, birthweight, and specific gravity reveal that the phthalate metabolites MCNP, MEHHP, and MEOHP were significantly associated with slower NNS frequencies, while MECPP, MEHHP, MEOHP, MONP, and MEHHTP were associated with higher NNS amplitudes (all p<0.05). In addition, MEHHP and MEOHP were also associated with fewer NNS cycles/min (p<0.05). Conclusions: These preliminary data suggest that certain features of infant suck, particularly NNS frequency and amplitude, are associated with in utero exposure to several phthalates, particularly di(2-ethylhexyl) phthalate. Results from this study will be the first to prospectively determine the sensitivity of NNS as an early indicator of exposure-related changes in neurodevelopment.