Women’s Health
Interconceptional Exposure to Common Plasticizers and Fetal Growth Akhgar Ghassabian* Kim Nail Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Cajachagua Torres Department of Pediatrics, New York University Grossman School of Medicine, New York, USA
Maternal exposure to common plasticizers prior to conception may impact fetal growth, but evidence remains limited. Participants were women enrolled with two successive pregnancies in a NYC birth cohort (2016-2021, interpregnancy interval median=2.5 years, 90% range=0.99-4.9). Exposure data from the first pregnancy (up to three measurements) were used as the interconceptional exposure for the second pregnancy, for which fetal growth and birth outcome data were available in 139 and 173 dyads, respectively. We averaged concentrations of urinary phthalate metabolites and bisphenols across timepoints, adjusted for urinary dilution, and natural log-transformed them. Repeated fetal biometry measures from clinical ultrasounds were used to predict growth parameters at 20, 30, and 36 weeks using linear mixed-effects models assuming nonlinear effects of gestational age. Information on birth outcomes was obtained from electronic health records. We used mixed models to test associations with fetal growth across gestation and linear regression for birth outcomes. Interactions with fetal sex was significant, so we conducted sex-stratified models. In male fetuses, higher maternal interconceptional levels of mono-ethyl phthalate were positively associated with estimated fetal weight, biparietal diameter, and head circumference. We also found positive associations of mono(2-ethylhexyl) phthalate with abdominal circumference and femur length. In contrast, higher mono-(2-carboxyheptyl) phthalate was associated with shorter femur length. In female fetuses, higher mono(2-carboxymetylhexyl) phthalate was associated with smaller abdominal circumference. Interconceptional levels of phthalate metabolites were positively associated with gestational length but negatively associated with birth length z-scores. There were no associations with bisphenols. Interconceptional exposure to phthalates may influence fetal growth, with males and females affected differently.