Time-to-Pregnancy Associated With Couples' Use of Tobacco Products

• Type of Material: Article
• Authors: Katherine J. Sapra, Eunice Kennedy Shriver National Institute of Child Health and Human Development; Dana Barr, Emory University; José M. Maisog, Glotech, Inc.; Rajeshwari Sundaram, Eunice Kennedy Shriver National Institute of Child Health and Human Development; Germaine M. Buck Louis, Eunice Kennedy Shriver National Institute of Child Health and Human Development
• Language: English
• Date: 2016-11
• Publisher: Oxford University Press (OUP): Policy B - Oxford Open Option C
• Publication Version: Final Published Version
• Copyright Statement: Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.
• License: Creative Commons Creative Commons CC0 1.0 Universal
• Final Published Version (URL): http://dx.doi.org/10.1093/ntr/ntw132
• Title of Journal or Parent Work: Nicotine and Tobacco Research
• ISSN: 1462-2203
• Volume: 18
• Issue: 11
• Start Page: 2154
• End Page: 2161
• Grant/Funding Information: This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (contracts N01-HD-3-3355;, N01-HD-3-3356;, and N01-HD-3-3358;, HHSN27500001).
• Keywords: FERTILITY; PERSISTENT ENVIRONMENTAL-POLLUTANTS; SOCIAL DETERMINANTS; Public, Environmental & Occupational Health; UNITED-STATES; INFERTILITY EVALUATION; CONSUMPTION; WOMEN; CIGARETTE-SMOKING; FECUNDABILITY; Life Sciences & Biomedicine; Substance Abuse; Science & Technology; SEMEN QUALITY
• Research Categories: Health Sciences, Public Health; Health Sciences, Obstetrics and Gynecology

Abstract

Introduction: Previous studies suggest female smoking increases time-to-pregnancy (TTP), a couple-dependent reproductive outcome, while associations with male smoking are more ambiguous. Furthermore, despite small increases in smokeless tobacco use in the United States, no prior study has evaluated TTP among smokeless tobacco users. Methods: Using population-based sampling in 16 counties in Michigan and Texas, 501 couples discontinuing contraception to become pregnant were followed until positive pregnancy test or 12 months of trying. Participants were interviewed on lifetime and current cigarette, cigar, and chew/snuff (smokeless) use and provided blood samples for quantification of heavy metals and cotinine. Fecundability odds ratios (FORs) and 95% confidence intervals (95% CIs) were estimated, adjusted for demographics/lifestyle. FORs less than 1 reflect longer TTP. Results: Eleven percentage of females and 15% of males smoked cigarettes. Among men, 14% smoked cigars, 9% used snuff, and 2% used chew. Compared with never tobacco users, male (FOR: 0.41, 95% CI: 0.24, 0.68) and female (FOR: 0.53, 95% CI: 0.33, 0.85) smoking were individually associated with longer TTP; males' smoking remained significant (FOR: 0.46, 95% CI: 0.27, 0.79) when modeling partners together. Cadmium levels were higher in smokers than smokeless tobacco and never users; adjusting for cadmium attenuated the cigarette-TTP association, particularly among women. TTP was shorter among smokeless tobacco users relative to smokers (FOR: 2.86, 95% CI: 1.47, 5.57). Conclusions: Compared with never users, smokeless tobacco did not alter TTP in our cohort; however, TTP was shorter compared with smokers. We observed longer TTP in male and female smokers; cadmium may partially contribute. Implications: Both partners' preconception smoking contributed to longer TTP, highlighting the importance of both partners' lifestyles in healthy reproduction and underscores the need for couple-based preconception guidance. The male's contribution is a new finding. Higher cadmium levels may partially contribute to longer TTP in smokers, particularly among females. Though we do not observe longer TTP among a small sample of smokeless tobacco users compared with never tobacco users, we observe shorter TTP compared with smokers. Further work is needed to more thoroughly delineate the relationship between smokeless tobacco use and TTP and possible mechanisms of tobacco use's effects on reproduction.