New Delhi: Tobacco smoking may significantly reduce the chances of having a baby, with evidence linking it to infertility in women, impaired sperm quality and sexual function in men, and poorer outcomes from fertility treatment, the World Health Organization (WHO) said in a new knowledge summary released Tuesday.
Globally, one in six people of reproductive age experience infertility at some point in their lives. WHO defines infertility as failure to achieve pregnancy after 12 months or more of regular unprotected sex.
A review of studies conducted between 2000 and 2026 found that women who currently smoke tobacco had a 40% higher risk of infertility compared with those who did not smoke. The evidence also suggests that quitting can make a difference: women who had smoked previously but were no longer smoking had a 25% lower risk of infertility than women who continued to smoke.
The impact is not limited to women. A review of 44 studies involving more than 60,000 men found smoking was associated with reproductive dysfunction, including abnormalities in semen and sexual function. Male smokers were more likely to have erectile and ejaculation problems, as well as poor sperm motility and abnormal sperm shape.
Smoking may also reduce the chances of success among couples undergoing assisted reproduction. WHO cited evidence from 21 studies linking cigarette smoking with fewer pregnancies and live births following fertility treatment, including in-vitro fertilisation, with some findings suggesting that successful outcomes may be roughly halved among smokers.
Importantly, people do not necessarily have to smoke themselves to face potential reproductive risks. WHO said second-hand tobacco smoke may increase the risk of infertility in women and reduce the chance of conceiving in a given month.
The evidence is strongest for conventional cigarette smoking, while research on newer products such as e-cigarettes, waterpipes and smokeless tobacco is still emerging. WHO cautioned that other tobacco and nicotine products may also pose fertility risks, although more research is needed.
WHO has recommended that healthcare providers counsel individuals and couples planning pregnancy about the reproductive risks of tobacco use and offer evidence-based support to quit. It has also called for brief advice on quitting to be routinely provided to tobacco users across healthcare settings.
