Tobacco smoking may reduce the chances of having a baby, according to a new World Health Organization (WHO) knowledge summary.
The publication highlights evidence linking tobacco use to infertility in women, harmful effects on sperm and sexual function in men, and potentially lower success rates with some fertility treatments. It also warns that exposure to second-hand smoke may affect fertility.
According to WHO, one in six people of reproductive age worldwide will experience infertility at some point in their lifetime. Infertility is defined as the failure to achieve pregnancy after 12 months or more of regular unprotected sex.
The publication cites decades of evidence showing that smoking can harm women’s reproductive health. A systematic review of studies conducted between 2000 and 2026 found that women who currently smoke tobacco have a 40% higher risk of infertility compared to those who do not smoke.
The publication also notes that women who smoked tobacco in the past but are not currently smoking may have a 25% lower risk of infertility compared with women who continue to smoke. This finding suggests that stopping smoking may improve reproductive health.
Infertility is not only a women’s health issue. The publication cites a recent review of 44 studies involving more than 60, 000 men, which found that smoking was associated with reproductive dysfunction, including semen abnormalities and sexual dysfunction.
The evidence indicated that men who smoke were more likely to have erectile dysfunction, ejaculation problems, as well as reproductive issues such as absence of sperm in semen, poor sperm motility and abnormal sperm shape.
For people undergoing fertility treatment, tobacco smoking may also reduce the chances of success. The publication cites earlier research from 21 studies that found cigarette smoking was associated with fewer live births and fewer pregnancies following assisted reproductive procedures, including in vitro fertilisation (IVF). The findings suggest that cigarette smoking may roughly halve the chances of a successful outcome.
WHO also warns that exposure to second-hand tobacco smoke may increase the risk of infertility. Women exposed to second-hand smoke may have a higher risk of infertility and a lower chance of conceiving during each month they try.
Evidence on newer products, including e-cigarettes, waterpipes and smokeless tobacco, is still emerging.
While the evidence is strongest for cigarette smoking, WHO warns that other tobacco and nicotine products may also pose risks to fertility and require further research.
WHO recommends that health-care providers inform individuals and couples planning pregnancy about the reproductive risks of tobacco use and offer evidence-based support to help them quit. It also recommends that brief advice on quitting be consistently provided to all tobacco users across healthcare settings.
