Vaping affects male fertility, but less than smoking

A difference in fertility treatment outcomes between couples where the male partner smokes cigarettes and those who vape has been revealed by new research.

Researchers in South Korea reported sperm quality and live-birth outcomes for both categories of male partners. Results showed a higher live birth rate in the vaping group compared to the conventional cigarette group, as well as higher sperm motility. Sperm concentration was higher in the conventional cigarette group, however. Other parameters remained consistent across both groups.

'The clinical miscarriage rate was significantly higher in the conventional cigarette group than in the E-cigarette group (36 percent vs 12 percent). The live birth rate was significantly higher in the E-cigarette group (56 percent vs 41 percent)', wrote the researchers from CHA University, Goyang, in their paper published in Nature Scientific Reports.

The researchers looked at records from couples undergoing IVF and ICSI cycles between May 2022 and January 2024. These included 151 men who were conventional cigarette smokers and 145 E-cigarette smokers; all had female partners who were non-smokers. Couples with additional infertility factors, such as poor ovarian response, endometriosis, adenomyosis, recurrent pregnancy loss, recurrent implantation failure, or advanced maternal/paternal age, were excluded from the study, as were men with significant medical history or previously noted abnormal semen analyses.

Clinical assessments of the male partners included age, height, body weight, method of smoking/vaping, frequency of smoking/vaping, medical history, physical examination, semen analysis, and hormone profiles.

The World Health Organisation states that the global prevalence of conventional cigarette smoking has been steadily declining, from 33 percent in 2000 to an expected 20 percent this year. Conversely, vaping is growing in popularity worldwide. The health risks and reproductive impact of smoking cigarettes are generally well known; however research on the impact of vaping is limited.

The authors added: 'Given that E-cigarettes are often perceived as an alternative to conventional smoking, further research is necessary to explore their effects on gamete quality and function to compare these impacts with those observed in nonsmokers'.