weight and head circumference at birth in function of placental paraben load in belgium an environage birth cohort study background parabens are a group of esters of parahydroxybenzoic acid utilized as antimicrobial preservatives in many personal care products epidemiological studies regarding the adverse effects of parabens on fetuses are limited the aim of this study was to determine the association between placental paraben exposure and birth outcomes we assessed paraben concentrations in placental tissue which potentially gives a better understanding of fetal exposure than the maternal urinary concentrations which are the current golden standardmethods placental tissue was collected immediately after birth from 142 motherchild pairs from the environage birth cohort the placental concentrations of four parabens methyl mep ethyl etp propyl prp and butyl bup were determined by ultraperformance liquid chromatography coupled with tandem massspectrometry generalized linear regression models were used to determine the association between paraben exposure levels and birth outcomesresults the geometric means of placental mep etp prp and bup were 184 216 168 and 005ngg tissue respectively the sum of parabens parabens including mep etp and prp was negatively associated with birth weight in newborn girls 166g 95 ci 322 86 p004 after adjustment for a priori selected covariates the sum of parabens was negatively associated with head circumference 06cm 95 ci 11 02 p0008 and borderline associated with birth length 06cm 95 ci13 01 p008 in newborn girls the placental concentration of etp was negatively associated with head circumference 06cm 95 ci11 01 p001 and borderline significantly associated with birth weight and birth length lastly placental etp and parabens were negatively associated with placental weight in newborn girls but not in newborn boys 453g 95 ci862 44 p003conclusion the negative association between maternal paraben exposure and birth outcomes warrants further research and followup over time to determine long term effects of gestational exposure to parabens