The effects of cigarette smoking on male fertility.

Cigarette smoking, one of the main causes of preventable morbidity and mortality, has a multitude of well-known side effects. The relationship between cigarette smoking and infertility has been studied for decades; however, large-scale, population-wide prospective studies are lacking. The majority of the current literature is in the form of retrospective studies focused on the effects of smoking on semen analyses. This article discusses the results of these studies and reviews the postulated mechanisms. The effects of smoking on assisted reproduction and in vitro fertilization outcomes are noted. The consequences of smoking while pregnant on future fertility as well as the outcomes of second-hand smoke are analyzed. The current evidence suggests that men should be advised to abstain from smoking in order to improve reproductive outcomes.