Urinary paraben concentrations among pregnant women and their matching fetuses, and the association with health damages

Abstract

Parabens have been used in multiple products including personal care products, pharmaceuticals, and foods for more than 50 years but several studies have raised concerns on their safety. The present study was designed to determine urinary paraben levels among pregnant women and their matching fetuses, and the association between paraben levels and stress markers. Pregnant women (n=46) and their matching children were recruited from four university hospitals located in Seoul, Ansan and Jeju of Korea, 2011. Parabens including methyl paraben (MP), ethyl paraben (EP), n-propyl paraben (PP), and n-butyl paraben (BP) were measured in urine using an automatic, high throughput online SPE-LC-MS/MS method. Urinary concentrations were normalized with specific gravity. Free cortisol, malondealdehyde (MDA) and 8 -hydroxydeoxyguanosine (8-OHdG) were measured in urine as stress marker and the transcription of NOX1 gene in placenta was quantified using quantitative PCR. Urinary MP was detected as the highest, and BP was detected as the lowest paraben in urine samples of both pregnant women and their fetuses. The levels of urinary parabens among Korean pregnant women are comparable to those reported elsewhere, except for EP which was 4-9 folds higher than pregnant women of other countries. The ratios of fetal to maternal paraben concentrations varied between 0.5 and 0.6 for MP and PP, but approximately 10 fold lower for EP. Urinary MP or EP levels were associated with several oxidative stress related biomarkers such as urinary 8-OHdG and MDA, even after the adjustment of relevant covariates such as maternal age, mode of delivery, pre-pregnancy BMI, gestational age and parity. This is the first study that reported the levels of major parabens in the first urines of newborn infants. Further studies are warranted to understand the implications of paraben exposure among biologically susceptible human populations.