Cigarette Smoking and Semen Quality: A New Meta-analysis Examining the Effect of the 2010 World Health Organization Laboratory Methods for the Examination of Human Semen.

Approximately 37% of men of reproductive age smoke cigarettes, with Europe having the highest tobacco use among all the World Health Organization (WHO) regions. Toxins from tobacco smoking can potentially affect sperm development and function, with a negative effect on semen parameters. Given the high prevalence of smoking and recent changes in the WHO laboratory methods for the examination of human semen, the role of this exposure in face of new WHO methods needs to be clarified. We conducted a systematic review, followed by a meta-analysis, to determine whether cigarette smoking affects human semen parameters. PubMed, Saint Joseph's University Discover, and Google Scholar were used to identify relevant studies published after release of the latest WHO methods for laboratory evaluation of human semen. Participants were from fertility/urologic clinics and andrology laboratories. The outcome measures were semen volume, sperm concentration, motility, and morphology, the parameters usually used in clinical settings to assess fertility. Twenty studies with 5865 participants were included in the meta-analysis. Exposure to cigarette smoking was associated with reduced sperm count (mean difference [MD]: -9.72×106/ml; 95% confidence interval [CI], -13.32 to -6.12), motility (MD: -3.48%; 95% CI, -5.53 to -1.44), and morphology (MD: -1.37%; 95% CI, -2.63 to -0.11). Subgroup analyses indicated that effect size was higher in infertile men than in the general population and in moderate/heavy smokers than in mild smokers. The overall effect size on semen volume, sperm count, and motility remained similar when 2010 and earlier WHO manuals were used for semen analysis but was lower with regard to sperm morphology. Our results suggest that cigarette smoking has an overall negative effect on semen parameters. The latest WHO laboratory methods for the examination of human semen had a minimal impact on the magnitude of effect size, thus confirming the observed negative effect of smoking on conventional semen parameters. A new systematic review and meta-analysis comprising 5865 men shows that cigarette smoking is associated with reduced sperm count and motility. Deterioration of semen quality is more pronounced in moderate and heavy smokers.

Sharma R ，Harlev A ，Agarwal A ，Esteves SC ... -  《-》

Synergistic effects of cigarette smoking and varicocele on semen parameters in 715 patients.

Mohamad Al-Ali B ，Eredics K 《-》

The effect of cigarette smoking on human seminal parameters, sperm chromatin structure and condensation.

Considerable debate still exists regarding the effects of cigarette smoking on male fertility. This work aimed to explore effects of cigarette smoking on semen parameters and DNA fragmentation on 95 infertile patients who were divided into infertile male nonsmokers (45) and infertile male smokers (50). Smokers were subdivided according to a number of cigarettes smoked per day into mild (≤10), moderate (11-20) and heavy smokers (≥21). Semen analysis, sperm chromatin condensation integrity with aniline blue staining and sperm viability were compared between the study groups. A significant decrease has been shown in sperm count (p = .006), progressive motility (p = <.001), percentage of normal forms (p = <.001) and viability (p = .002) between infertile nonsmoker and infertile smokers. The percentage of abnormal sperm chromatin condensation was significantly higher in smokers compared to nonsmokers (p = <.001). A linear correlation was detected between the extent of cigarette smoking and the degree of worsening in progressive motility (p = .001), total motility (p < .001), viability (p < .001) and normal morphology (p < .001). These results indicate that cigarette smoking has detrimental effects on semen parameters. It negatively affected all conventional semen parameters in addition to sperm chromatin condensation and sperm viability. These abnormalities were also proportional to the number of cigarettes smoked per day and to the duration of smoking.

Mostafa RM ，Nasrallah YS ，Hassan MM ，Farrag AF ，Majzoub A ，Agarwal A ... -  《-》

Tobacco smoking is associated with decreased semen quality.

Asare-Anane H ，Bannison SB ，Ofori EK ，Ateko RO ，Bawah AT ，Amanquah SD ，Oppong SY ，Gandau BB ，Ziem JB ... -  《Reproductive Health》

The effect of cigarette smoking on the semen parameters of infertile men.

De Brucker S ，Drakopoulos P ，Dhooghe E ，De Geeter J ，Uvin V ，Santos-Ribeiro S ，Michielsen D ，Tournaye H ，De Brucker M ... -  《-》