Bisphenol A, phthalates and couple fecundity, the life study

Abstract

ObjectiveAn evolving literature suggests that short-lived environmental chemicals may affect fecundity among couples undergoing in vitro fertilization, but less is known about effects on couples from the general population.DesignProspective cohort design with preconception recruitment of 501 couples discontinuing contraception for purposes of becoming pregnant, 2005-2009.Materials and MethodsUpon enrollment, couples completed interviews and anthropometric assessments and provided urine specimens for quantification of bisphenol A and 14 phthalate metabolites using performance liquid chromatography tandem mass spectrometry. Couples completed daily journals on intercourse and lifestyle, and women recorded menstruation and pregnancy test results. Couples were followed until a positive hCG pregnancy test or 12 cycles without pregnancy. Discrete Cox models estimated fecundability odds ratios (FORs) and 95% confidence intervals (CIs) for each chemical and partner adjusting for age, body mass index, serum cotinine, creatinine, and research site while accounting for time off contraception.ResultsFemale BPA concentration controlling for male BPA concentration was not associated with diminished fecundity (FOR 0.98; 95% CI 0.83, 1.15). Female mono (3-carboxypropyl) phthalate concentration was associated with an elevated FOR or shorter TTP (1.30; 95% CI 1.08, 1.58). Conversely, concentrations of monomethyl, mono-n-butyl and monobenzyl phthalates in males were associated with diminished couple fecundability as reflected in longer TTPs (FOR=0.80, 95% CI 0.69, 0.93; FOR=0.81, 0.68, 0.97; and FOR=0.77, 0.64 0.92, respectively).ConclusionMale but not female phthalate concentrations may be associated with approximately a 20% reduction in fecundity. The findings underscore the importance of using a couple based designs for assessing couple dependent outcomes such as pregnancy to minimize erroneous study conclusions. ObjectiveAn evolving literature suggests that short-lived environmental chemicals may affect fecundity among couples undergoing in vitro fertilization, but less is known about effects on couples from the general population. An evolving literature suggests that short-lived environmental chemicals may affect fecundity among couples undergoing in vitro fertilization, but less is known about effects on couples from the general population. DesignProspective cohort design with preconception recruitment of 501 couples discontinuing contraception for purposes of becoming pregnant, 2005-2009. Prospective cohort design with preconception recruitment of 501 couples discontinuing contraception for purposes of becoming pregnant, 2005-2009. Materials and MethodsUpon enrollment, couples completed interviews and anthropometric assessments and provided urine specimens for quantification of bisphenol A and 14 phthalate metabolites using performance liquid chromatography tandem mass spectrometry. Couples completed daily journals on intercourse and lifestyle, and women recorded menstruation and pregnancy test results. Couples were followed until a positive hCG pregnancy test or 12 cycles without pregnancy. Discrete Cox models estimated fecundability odds ratios (FORs) and 95% confidence intervals (CIs) for each chemical and partner adjusting for age, body mass index, serum cotinine, creatinine, and research site while accounting for time off contraception. Upon enrollment, couples completed interviews and anthropometric assessments and provided urine specimens for quantification of bisphenol A and 14 phthalate metabolites using performance liquid chromatography tandem mass spectrometry. Couples completed daily journals on intercourse and lifestyle, and women recorded menstruation and pregnancy test results. Couples were followed until a positive hCG pregnancy test or 12 cycles without pregnancy. Discrete Cox models estimated fecundability odds ratios (FORs) and 95% confidence intervals (CIs) for each chemical and partner adjusting for age, body mass index, serum cotinine, creatinine, and research site while accounting for time off contraception. ResultsFemale BPA concentration controlling for male BPA concentration was not associated with diminished fecundity (FOR 0.98; 95% CI 0.83, 1.15). Female mono (3-carboxypropyl) phthalate concentration was associated with an elevated FOR or shorter TTP (1.30; 95% CI 1.08, 1.58). Conversely, concentrations of monomethyl, mono-n-butyl and monobenzyl phthalates in males were associated with diminished couple fecundability as reflected in longer TTPs (FOR=0.80, 95% CI 0.69, 0.93; FOR=0.81, 0.68, 0.97; and FOR=0.77, 0.64 0.92, respectively). Female BPA concentration controlling for male BPA concentration was not associated with diminished fecundity (FOR 0.98; 95% CI 0.83, 1.15). Female mono (3-carboxypropyl) phthalate concentration was associated with an elevated FOR or shorter TTP (1.30; 95% CI 1.08, 1.58). Conversely, concentrations of monomethyl, mono-n-butyl and monobenzyl phthalates in males were associated with diminished couple fecundability as reflected in longer TTPs (FOR=0.80, 95% CI 0.69, 0.93; FOR=0.81, 0.68, 0.97; and FOR=0.77, 0.64 0.92, respectively). ConclusionMale but not female phthalate concentrations may be associated with approximately a 20% reduction in fecundity. The findings underscore the importance of using a couple based designs for assessing couple dependent outcomes such as pregnancy to minimize erroneous study conclusions. Male but not female phthalate concentrations may be associated with approximately a 20% reduction in fecundity. The findings underscore the importance of using a couple based designs for assessing couple dependent outcomes such as pregnancy to minimize erroneous study conclusions.