The prevalence of positive urinary cotinine tests in Korean infertile couples and the effect of smoking on assisted conception outcomes

Objective: Smoking has been reported to harm nearly every organ of the body, but conflicting results have been reported regarding the effects of smoking on assisted conception. In this prospective cohort study, we aimed to investigate the prevalence of positive urinary cotinine tests in infertile couples and whether cotinine positivity was associated with infertility treatment outcomes. Methods: A qualitative urinary cotinine test was administered to 127 couples who underwent in vitro fertilization (IVF, n=92) or intrauterine insemination (IUI, n=35). Results: The overall prevalence of positive urinary cotinine test was 43.3% (55/127) in the male partners and 10.2% (13/127) in the female partners with similar prevalence rates in both genders in the IUI and IVF groups. Semen characteristics, serum markers of ovarian reserve, and number of retrieved oocytes were comparable among cotinine-positive and cotinine-negative men or women (with the exception of sperm count, which was higher among cotinine-positive men). The results of urinary cotinine tests in infertile couples were not associated with IVF and IUI outcomes. Conclusion: The presence of cotinine in the system, as indicated by a positive urinary cotinine test, was not associated with poorer outcomes of infertility treatment.