Effect of Smoking on Male Infertility: A Narrative Review

Abstract

The harmful impact of smoking on health and functioning systems is well-documented and widely recognized. The harmful effects of smoking extend beyond health. Including a significant increase in the risk of male infertility. This, in turn, has effects on various dimensions such as social, psychological, and economic aspects, and contributes to a major decline in population growth. Globally, fertility rates have been dramatically decreasing over the past few decades. Fertility issues are attributed equally to both male and female partners, with each contributing to approximately 30% of overall infertility cases. In male infertility, a variety of factors can play a role in infertility. However, 15% of male infertility cases have unknown causes. This is referred to as idiopathic male infertility, where no identified medical, genetic, or environmental conditions are found, yet, conception remains unachieved. Semen analysis remain the standard technique for evaluating male infertility. Semen parameters consist of several measurements, the most essential ones are semen volume, total sperm count, sperm motility, sperm morphology, and semen vitality. These basic parameters are key influencers of male infertility and give insight towards the reproductive health condition. Numerous studies have explored the relationship between smoking and male infertility, demonstrating that smoking negatively impacts male fertility through many aspects, mainly causing an increase in reactive oxygen species production and thereby resulting in oxidative stress, this is caused by chemical ingredients that are present in tobacco and cigarettes. Additionally, smoking causes alteration of cellular DNA leading to altered cellular functions. This review highlights the effect of smoking on semen parameters which are the main indicators for male infertility. A review of literature and clinical studies was conducted to fully comprehend the relationship between cigarette and tobacco smoking and male infertility, and to investigate its extended consequence to the male reproductive system. Furthermore, it recommends appropriate approaches in improving semen parameters and male infertility in general.