Serum phthalate levels and time to pregnancy in couples from Greenland, Poland and Ukraine.

Ina Olmer Specht,Jens Peter Bonde,Gunnar Toft,Christian H Lindh,Bo A G Jönsson,Kristian T Jørgensen,Jodi Pawluski

doi:10.1371/journal.pone.0120070

Ina Olmer Specht, Jens Peter Bonde + Show 5 more

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https://doi.org/10.1371/journal.pone.0120070

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Abstract

Phthalates are ubiquitous industrial chemicals that have been associated with altered reproductive function in rodents. Several human studies have reported an inverse association between male testosterone and phthalate levels. Our aim was to investigate time to pregnancy (TTP) according to serum levels of diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP) metabolites in both partners. In 2002-2004 we enrolled 938 pregnant women and 401 male spouses from Greenland, Poland and Ukraine. Six oxidized metabolites of DEHP and DiNP were summarized for each of the two parent compounds to provide proxies of the internal exposure. We used Cox discrete-time models to estimate fecundability ratios (FR) and 95% confidence intervals (95% CIs) for men and women according to their proxy-DEHP or -DiNP serum levels adjusted for a fixed set of covariates.The FR was slightly elevated among women with high levels of DEHP (FR=1.14, 95% CI 1.00;1.30) suggesting a shorter TTP in these women. The FR was unrelated to DiNP in women, whereas the results for men were inconsistent pointing in opposite directions. First-time pregnant women from Greenland with high serum DiNP levels had a longer TTP. This study spanning large contrast in environmental exposure does not indicate adverse effects of phthalates on couple fecundity. The shorter TTP in women with high levels of DEHP metabolites is unexplained and needs further investigation.

Highlights

The probability of conceiving in a given menstrual cycle can be affected by several factors including age, body mass index (BMI), tobacco smoking, and alcoholic beverages [34; 35]
The fecundability ratios (FR) was slightly elevated among women with high levels of diethylhexyl phthalate (DEHP) (FR=1.14, 95% confidence intervals (95% CIs) 1.00;1.30) suggesting a shorter time to pregnancy (TTP) in these women
We have previously reported a negative association between serum levels of DEHP and diisononyl phthalate (DiNP) metabolites and male testosterone, semen volume and total sperm count [40]

Summary

Introduction

The probability of conceiving in a given menstrual cycle can be affected by several factors including age, body mass index (BMI), tobacco smoking, and alcoholic beverages [34; 35]. Some studies have shown that environmental and occupational contaminants can affect the time to pregnancy (TTP) [9; 12; 39]. Chemicals that influence TTP may subsequently influence birth outcomes, and studies have shown that maternal exposure to environmental. Serum Phthalate Levels and Time to Pregnancy design, data collection and analysis, decision to publish, or preparation of the manuscript

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