Prenatal exposure to phenols and fetal growth across pregnancy

BACKGROUND AND AIM: Phenols are endocrine disrupting chemicals hypothesized to affect fetal growth. Previous studies have primarily examined their effects on size at delivery and few have included ultrasound measures of growth. We investigated associations between prenatal phenol exposure and ultrasound and delivery measures of fetal growth. METHOD: Using the LIFECODES Fetal Growth Study (n = 900), we estimated exposure to 12 phenols using urine samples collected at three timepoints during pregnancy. We abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated the mean difference (95% confidence interval [CI]) in repeated ultrasound measures of fetal growth for an interquartile range (IQR)-increase in each phenol using linear mixed effects models. We estimated the mean difference (95% CI) in birthweight z-score and odds ratio (OR) (95% CI) of having a small- or large-for-gestational age birth for an IQR-increase in each phenol using linear and logistic regression models, respectively. RESULTS: Exposure to 2,4-dichlorophenol, benzophenone-3, and triclosan was positively associated with multiple ultrasound measures of fetal growth, including head and abdominal circumference, femur length, and estimated fetal weight (EFW) z-scores. For example, triclosan was associated with a 0.09 (95% CI: 0.01, 0.18) higher EFW z-score, corresponding to a 21 g increase in EFW at 30 weeks gestation. Associations were attenuated at delivery, but triclosan remained positively associated with birthweight z-scores (mean difference: 0.13, 95% CI: 0.02, 0.25). Methylparaben was also positively associated with small-for-gestational age births (OR: 1.45, 95% CI: 1.06, 1.98). CONCLUSIONS: We observed associations between some biomarkers of phenol exposure and ultrasound measures of fetal growth, though associations at the time of delivery were attenuated. These findings are consistent with hypotheses that environmental phenols have the potential to affect growth during the prenatal period.

Impact/Purpose

This presentation is for an accepted talk at the 36th Annual Meeting for the International Society of Environmental Epidemiology. It will be given during a session on Prenatal Exposure and Neonatal Outcomes. It will cover novel methodologies in the study of fetal growth, namely, analysis of longitudinal ultrasound measures of fetal growth and their associations with environmental phenol exposures during pregnancy.   

Citation

Bommarito, P., D. Stevens, B. Welch, J. Meeker, D. Cantonwine, T. McElrath, AND K. Ferguson. Prenatal exposure to phenols and fetal growth across pregnancy. 36th Annual Meeting of the International Society of Environmental Epidemiology, Santiago, CHILE, August 25 - 28, 2024.