Biomarkers of Exposure to Phthalate Mixtures and Adverse Birth Outcomes in a Puerto Rico Birth Cohort.

Background: Humans are exposed to complex mixtures of phthalate chemicals from a range of consumer products. Previous studies have reported significant associations between individual phthalate metabolites and pregnancy outcomes, but mixtures research is limited.

Objectives: We used the Puerto Rico Testsite for Exploring Contamination Threats longitudinal pregnancy cohort to investigate associations between phthalate metabolite mixtures and pregnancy outcomes.

Mediation by hormone concentrations on the associations between repeated measures of phthalate mixture exposure and timing of delivery.

Background: Phthalates are used in the manufacturing of consumer products, resulting in ubiquitous human exposure to phthalate mixtures. Previous work has suggested that phthalates display endocrine-disrupting capabilities, and exposure is associated with early delivery.

Objective: To assess mediating effects of hormone concentrations on associations between phthalate mixtures and preterm birth (PTB).

Gestational Hormone Concentrations Are Associated With Timing of Delivery in a Fetal Sex-Dependent Manner.

Background: Early delivery remains a significant public health problem that has long-lasting impacts on mother and child. Understanding biological mechanisms underlying timing of labor, including endocrine disruption, can inform prevention efforts.

Methods: Gestational hormones were measured among 976 women in PROTECT, a longitudinal birth cohort in Puerto Rico.

Individual and joint effects of phthalate metabolites on biomarkers of oxidative stress among pregnant women in Puerto Rico.

Exposures to phthalate compounds have been linked to adverse birth outcomes, potentially through oxidative stress mechanisms. We explored associations between mixtures of biomarkers of phthalate and phthalate replacement metabolites and oxidative stress using lipid peroxidation biomarker 8-iso-prostaglandin-F2α (8-iso-PGF2α). As 8-iso-PGF2α can be generated via both chemical (nonenzymatic) and enzymatic lipid peroxidation pathways, we calculated the ratio of 8-iso-PGF2α/prostaglandin F2α in an attempt to distinguish the potential contributions of the two pathways.

Polycyclic aromatic hydrocarbon exposure results in altered CRH, reproductive, and thyroid hormone concentrations during human pregnancy.

Polycyclic aromatic hydrocarbons (PAHs) are byproducts of incomplete combustion reactions and are ubiquitous in the environment, leading to widespread human exposure via inhalation and ingestion pathways. PAHs have been implicated as endocrine disrupting compounds in previous animal and in vitro studies, but human studies are currently lacking. Pregnant women and their developing fetuses are particularly susceptible populations to environmental contaminants, in part because alterations in hormone physiology during gestation can have adverse consequences on the health of the pregnancy.

Interactions between chemicals and non-chemical stressors: The modifying effect of life events on the association between triclocarban, phenols and parabens with gestational length in a Puerto Rican cohort.

Background: Phenols and parabens are common additives to consumer products. There is evidence of adverse birth outcomes in association with prenatal exposure to these chemicals, in addition to psychosocial factors. We previously reported an increase in gestational length with bisphenol-A, methylparaben and propylparaben, and a decrease in gestational length with triclocarban.

Associations of Phthalates and Phthalate Replacements With CRH and Other Hormones Among Pregnant Women in Puerto Rico.

Context: Phthalates are endocrine-disrupting chemicals that may be associated with adverse birth outcomes. Dysregulation of maternal endocrine homeostasis could be a possible biological pathway between phthalates and birth outcomes.

Objective: Examine associations between 19 maternal urinary phthalate or phthalate replacement metabolites and 9 serum hormones measured over two time points during pregnancy.

A repeated measures study of phenol, paraben and Triclocarban urinary biomarkers and circulating maternal hormones during gestation in the Puerto Rico PROTECT cohort.

Introduction: Prenatal exposure to some phenols and parabens has been associated with adverse birth outcomes. Hormones may play an intermediate role between phenols and adverse outcomes. We examined the associations of phenol and paraben exposures with maternal reproductive and thyroid hormones in 602 pregnant women in Puerto Rico.

The associations between prenatal exposure to triclocarban, phenols and parabens with gestational age and birth weight in northern Puerto Rico.

Background: Prenatal exposure to certain xenobiotics has been associated with adverse birth outcomes. We examined the associations of triclocarban, phenols and parabens in a cohort of 922 pregnant women in Puerto Rico, the Puerto Rico Testsite for Exploring Contamination Threats Program (PROTECT).

Methods: Urinary triclocarban, phenols and parabens were measured at three time points in pregnancy (visit 1: 16-20 weeks, visit 2: 20-24 weeks, visit 3: 24-28 weeks gestation).