Maternal phthalate urine concentrations, fetal growth and adverse birth outcomes. A population-based prospective cohort study

Exposure to phthalates may affect fetal growth, but previous studies are inconsistent and have not explored the trimester-specific effects of on repeated measures growth. To assess associations maternal phthalate metabolites urine concentrations with growth birth outcomes identify potential windows vulnerability exposure. Population-based prospective cohort study, Generation R Study (2002–2006). Data analysis was performed from November 2019 June 2020. Rotterdam, Netherlands. 1379 pregnant women. Maternal in first, second third trimester. Fetal head circumference, length weight measured trimester by ultrasound at preterm small size for gestational age birth. Higher pregnancy-averaged phthalic acid, low molecular (LMWP), high (HMWP) di-2-ethylhexylphthalate (DEHP) tended be associated lower SDS across gestation. The acid LMWP became stronger as pregnancy progressed (differences ?0.08 (95% CI ?0.14 ?0.02) ?0.09 ?0.16 40 weeks per interquartile range increase LMWP, respectively). specific HMWP DEHP were also smaller circumference an increased risk (p-values < 0.05). We observed differences timing exposure these associations. seem related restriction Phthalates outcomes. Further needed explore underlying mechanisms long-term consequences.