Hormonal Changes at Early Age and Prenatal Exposure to Phthalates and Bisphenol A in a Cohort of Cuernavaca, Morelos, Mexico

Abstract

Has been suggested that phthalate and BPA A exposure in utero may impact hormone concentrations and evolve the onset of early puberty. The objective of this study was to evaluate the association between prenatal exposures to phthalates and hormonal levels at 9 years old in a Cuernavaca, Morelos birth cohort (POSGRAD study). In a subsample of 314 children, total testosterone hormone levels and dehydroepiandrosterone sulfate (DHEA-S) were measurements from serum samples at 9 years of age from both sex. These levels were contrasted with the concentrations of 9 different metabolites of phthalates [Mono-2-ethylhexyl phthalate (MEHP), Mono-2-ethyl-5-carboxypentyl phthalate (MECPP), Mono-2-ethyl-5-hydroxyethyl phthalate (MEHHP ), Mono-2-ethyl-5-oxohexyl phthalate (MEOHP), Mono-3-carboxypropyl phthalate (MCPP), Monobenzyl phthalate (MBzP), Monobutyl phthalate (MBP), Mono-iso-butyl phthalate (MiBP) and Mono ethyl phthalate (MEP)], and Bisphenol A in urine resulting from samples of mothers during the second trimester of pregnancy, through a multiple linear regression model adjusted for anthropometric variables of the child and sociodemographic characteristics.RESULTS. A significant relationship was observed with the LnMECPP and LnMEHHP with total testosterone levels, (increase of 13%, IC95%: 0.9%, 24%, and 11% increase, IC95% 0.16% to 23.6% en IU / L, by unit of increase in each metabolite, respectively. No metabolite showed a statistically significant association with DHEA-S levels, however, in girls who initiated menarche at 9 years old, significant association were observed with MiPB, MBzP and BPA with an increase of DHEA-S.DISCUSSION. Our results are consistent with previous studies in which it has been suggested that prenatal exposure can to induce can lead to early puberty. In our case, the exposure window was during the second trimester suggesting more prevention in this stage of life.