A case-control study of male infertility.

摘要

It is estimated that, in the United States, approximately 15% of couples are involuntarily infertile at some time during their reproductive lives. A male factor contributes to this condition, either wholly or partially, in about 50% of these couples. Epidemiologic studies designed specifically to investigate the association between male infertility and exposures or conditions known to have a deleterious effect on spermatogenesis are lacking. Using a case-control design, a study was undertaken to investigate the risk of clinical male infertility (primary and secondary), in men who demonstrated oligo-, astheno- and/or teratozoospermia. Cases and controls were 20-49 year old residents of King County Washington. The cases, identified from one of three infertility clinics during 1979-81, had not achieved conception after at least one year of unprotected intercourse. The female partner was without signs of fertility impairment. Controls were identified through a survey using area sampling methodology. A structured in-person interview was administered to all participants. Completion of the interview was accomplished for 85 of the 144 eligible cases (59%) and 142 of the 207 eligible controls (69%). The principal analyses included only controls with no history of vasectomy within one year of the study (98 men) and used unconditional multiple logistic regression to estimate odds ratios (OR) adjusted for potential confounding variables. There was an increased risk associated with a history of childhood cryptorchidism (OR = 10.9, 95%CI = 1.2{dollar}-{dollar}104.0), varicocele(OR = {dollar}infty{dollar}), hot tub use (OR = 5.7, 95%CI = 1.0{dollar}-{dollar}34.4), exposure to pesticides (OR = 15.2, 95%CI = 1.7{dollar}-{dollar}135.4), and a history of gonorrhea infection (OR = 5.0, 95%CI = 0.6{dollar}-{dollar}39.1). However, a small sample size and the various sources of potential selection bias inherent in the study limit the interpretations of these results. Nevertheless, these results suggest avenues for further research, and argue for the feasibility of the case-control design in pursuing the etiologies of male infertility.