Occurrence, distribution and potential sources of phthalate and non-phthalate plasticizers in maternal and fetal-related biological matrices.

Phthalate esters (PEs), widely used as plasticizers in consumer products, are endocrine disruptors and represent a significant source of exposure for pregnant women and the fetus. This study, conducted among 198 pregnant women from middle-class backgrounds and monitored in the maternity ward in Monastir hospital (Tunisia), assessed the concentrations of several PEs in maternal and fetal biological matrices to estimate exposure levels during pregnancy. GC-MS/MS chromatographic analyses were performed on maternal samples namely, placenta, amniotic fluid, urine, and blood. Seven plasticizers, including phthalates and non-phthalates alternatives were detected namely: diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP), di(2-ethylhexyl) terephthalate (DEHT), diisobutyl adipate (DiBA), dimethyl adipate (DMA). DEHT, was the most prevalent plasticizer despite being a "safer" alternative, with highest geometric mean concentration in urine (403.7 µg/kg), followed by placenta (318.6 µg/kg), blood (304.5 µg/kg), and amniotic fluid (275.0 µg/kg). Among phthalates, DiBP showed the highest concentrations in placental tissue (195.8 µg/kg) and urine (226.0 µg/kg), while DMP and DEP were mainly detected in amniotic fluid (128.2 and 64.8 µg/kg, respectively). Although the renal system contributes significantly to the elimination of these substances via urine, substantial amounts can cross the placental barrier and reach the fetus, thus posing a potential health risk. the findings highlight a clear maternal-fetal exposure continuum to PEs and underline the need for improved exposure control, especially for vulnerable populations, and support further evaluation of both PEs and their substitutes.