Hum. Reprod. Advance Access originally published online on October 21, 2008
Human Reproduction 2009 24(2):451-458; doi:10.1093/humrep/den373
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy
1 Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health & Human Development, 6100 Executive Blvd, Rm. 7B03, Rockville, MD 20852 2 Department of Mathematics & Statistics, University of North Carolina, Charlotte, 376 Fretwell Bldg, 9201 University City Blvd, Charlotte, NC 28223-0001 3 Division of Epidemiology, The Ohio State University College of Public Health, B218 320 W. 10th Avenue, Columbus, Ohio 43210 4 Department of Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, the State University of New York, Farber Hall, Room 102, 3435 Main St., Buffalo, NY 14214 5 Department Social & Preventive Medicine, University at Buffalo, 270 Farber Hall, 3435 Main St., Buffalo, NY 14214 6 Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, 800 Sumter Street, Columbia, SC 29201
7 Corresponding address. Tel: (301) 496-6155; Fax: (301) 402-2084; E-mail: louisg{at}mail.nih.gov
BACKGROUND: Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied.
METHODS: Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings—estrogenic, anti-estrogenic and other—and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs).
RESULTS: Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00).
CONCLUSIONS: These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.
Key words: time-to-pregnancy/polychlorinated biphenyls/fecundity/lifestyle/environment
Submitted on May 12, 2008; resubmitted on September 15, 2008; accepted on September 18, 2008.