Phthalates Biomarker Identification and Exposure Estimates in a Population of Pregnant Women

Abstract

Phthalates are known reproductive and developmental toxicants in experimental animals. However, in humans, there are few data on the exposure of pregnant women that can be used to assess the potential developmental exposure experienced by the fetus. We measured several phthalate metabolites in maternal urine, maternal serum, and cord serum samples collected at the time of delivery from 150 pregnant women from central New Jersey. The urinary concentrations of most metabolites were comparable to or less than among the U.S. general population, except for mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), three metabolites of di(2-ethylhexyl) phthalate (DEHP). The median urinary concentrations of MEHHP (109 μg/l) and MEOHP (95.1 μg/l) were more than 5 times their population-based concentrations, whereas the median urinary concentration of MEHP was more than 20 times higher. High concentration of MEHP may indicate a recent exposure to the parent chemical DEHP in the hospital shortly before the collection of the samples. Calculation of daily intakes using the urinary biomarker data reveals that none of the pregnant women tested had integrated exposures to DEHP greater than the NIH Public Access Author ManuscriptHum Ecol Risk Assess. Author manuscript; available in PMC 2010 August 2. Agency for Toxic Substances and Disease Registry's minimal risk levels (MRLs chronic 60, intermediate 100 μg/kg/day). No abnormal birth outcomes (e .g., birth weight, Apgar Score, and gestational age) were noted in those newborns whose mothers had relatively greater exposure to DEHP during the perinatal period than others in this study. Significantly greater concentrations and detection frequencies in maternal urine than in maternal serum and cord serum suggest that the urinary concentrations of the phthalate metabolites may be more reliable biomarkers of exposure than their concentrations in other biological specimens.

Prenatal Phthalate Exposures and Body Mass Index Among 4- to 7-Year-old Children

“…27 However, phthalate concentrations measured in cord blood are susceptible to contamination 6 and may arise from hospital-based exposures to DEHP at delivery. 28 Valvi et al 9 assessed associations between the average of first and third trimester maternal urinary summed low (∑LMWP: MEP, MnBP, MiBP) and high (∑HMWP: MBzP and 4 DEHP metabolites) molecular weight phthalate metabolites concentrations and childhood anthropometry in a Spanish birth cohort study. ∑HMWP metabolites concentrations were associated with weight gain z-scores in the first 6 months and BMI z-scores at ages 1, 4, and 7 years in a sex-specific manner (lower among boys, higher among girls), and supplemental analyses indicated stronger associations for ∑DEHP than MBzP.…”

Urinary phthalate and phthalate alternative metabolites and isoprostane among couples undergoing fertility treatment

“…However, in comparison with SG-adjusted values of women seeking infertility care who took part in the Environment and Reproductive Health study (Messerlian et al, 2016), MEHP concentrations in our female participants were twofold higher (8.0 ng/mL vs. 3.8 ng/mL), while concentrations of MEOHP (13.8 ng/ml vs. 12.1 ng/mL), MEHHP (19.7 ng/mL vs 18.8 ng/mL), and MECPP (27.8 ng/mL vs. 31.6 ng/mL) were similar. Medical interventions have previously been shown to contribute to urinary DEHP metabolite concentrations (Koch et al, 2005; Vandentorren et al, 2011; Yan et al, 2009) due to the presence of DEHP as a plasticizer in medical tubing and intravenous (IV) bags. We speculate that the higher concentrations of DEHP metabolites among females in our study are likely attributable to the timing of urine collection, which occurred either before or shortly after administration of IV tubing for oocyte retrieval procedures.…”

Season-dependent concentrations of urinary phthalate metabolites among Chinese pregnant women: Repeated measures analysis

“…Therefore, humans are constantly exposed to phthalates through ingestion, inhalation and dermal absorption (Wittassek et al, 2011). And their metabolites are detectable in various biospecimens, including urine, serum, breast milk, placental tissue, amniotic fluid and umbilical blood (Frederiksen et al, 2007;Hines et al, 2009;Jensen et al, 2012;Yan et al, 2009).…”