The WHO confirms a 40% increased risk of infertility in smokers.

The World Health Organization (WHO) published a new synthesis of the state of knowledge on September 8, 2026[1] The report, dedicated to tobacco and infertility ("Tobacco and infertility," a collection of WHO tobacco knowledge summaries), is based on a systematic review of studies published between 2000 and 2026. It concludes that female smokers have a 40% increased risk of infertility. Exposure to secondhand smoke also increases this risk, while in men, smoking is associated with sperm abnormalities and sexual dysfunction. The summary further indicates that smoking can halve the chances of successful infertility treatments, but that quitting smoking is associated with a 25% reduction in the risk of infertility in former smokers. With one in six people worldwide facing infertility during their lifetime, the WHO recommends that health professionals systematically inform patients and couples planning a pregnancy about the risks associated with tobacco and offer smokers smoking cessation support based on best practices.

One in six people worldwide are affected by infertility

The WHO defines infertility as a disease of the male or female reproductive system characterized by the absence of pregnancy after 12 or more months of regular, unprotected sexual intercourse. Globally, approximately one in six people of reproductive age experiences infertility at some point in their lives, and this prevalence does not vary significantly across regions or between high-income and low- or middle-income countries (17.8 per 100,000 live births versus 16.5 per 100,000 live births).

According to a large multicenter WHO study of 8,500 couples in 25 countries, infertility is attributable to female factors alone in 30.6% of cases, to male factors alone in 18.7%, and to a combination of both in 26.3%. In approximately 10% of cases, no cause is identified. Among the modifiable risk factors, the scientific literature highlights an unbalanced diet, a sedentary lifestyle, excessive alcohol consumption, and active and passive smoking.

A 40% increased risk of infertility (%) in female smokers

The link between smoking and female infertility has been documented for a long time: as early as 1979, the US Surgeon General's report noted that female smokers were more often infertile, and a 1998 systematic review estimated the risk of infertility in smokers to be 1.5 times that of non-smokers. The new systematic review conducted for the WHO on studies published between 2000 and 2026 confirms this association: the risk of infertility is 1.4 times higher in women who currently smoke. Specifically, while the risk of infertility is 15 per 100,000 for non-smokers, it reaches 21 per 100,000 for smokers.

The review highlights that quitting smoking improves the chances of conception: women who have smoked in the past but no longer smoke have a 25 times lower risk of infertility than current smokers. Passive smoking is also a risk factor: non-smoking women exposed to secondhand smoke have a 1.2 times higher risk of infertility and reduced chances of conception with each cycle.

Regarding other tobacco products and non-medicinal nicotine products, the WHO notes that the data remain incomplete. An American study of over 4,500 women linked e-cigarette use to a 20% decrease in fertility, and two studies including hookah (shisha) users highlighted an increased risk of infertility comparable to that of cigarettes. The WHO believes, however, that further high-quality research is needed to fully characterize the effects of hookah, smokeless tobacco, and nicotine products on fertility, while also noting that the presence of similar toxins in these products suggests that the underlying mechanisms may be the same.

In men, alterations in sperm and sexual function

In men, the link between smoking and infertility is generally established based on sperm parameters and sexual function. A recent review of 44 studies involving more than 60,000 men consistently associated smoking with an increase in reproductive dysfunction across the different populations studied. Smokers more frequently experienced erectile and ejaculatory problems than non-smokers, and smoking may increase the risk of azoospermia (absence of sperm), asthenozoospermia (reduced motility), and teratozoospermia (abnormal sperm morphology).

Studies have also linked hookah smoking to lower sperm quality (smaller volume, reduced motility, lower proportion of normally shaped sperm), although a more recent study found no effect on motility. Here again, the WHO calls for further research.

Infertility treatments are half as effective in smokers

Smoking also compromises the chances of success with infertility treatments (ovulation stimulation, surgery, in vitro fertilization, and other assisted reproductive technologies). By combining the results of 21 studies, researchers compared women who smoked and non-smokers who underwent this type of treatment. The finding is clear: with the same treatment, smokers are about half as likely to achieve pregnancy, and about half as likely to have a live birth. In other words, smoking can halve the effectiveness of a process that is often long, costly, and arduous. The WHO notes that a more recent but smaller study (approximately 300 women) found no difference based on smoking status or the use of e-cigarettes and hookahs, but this does not invalidate the overall findings.

WHO recommendations: inform, advise and support the weaning process

Based on its 2025 guideline on the prevention, diagnosis, and treatment of infertility, the WHO recommends that healthcare professionals inform individuals and couples planning a pregnancy about the reproductive risks of tobacco and offer smokers smoking cessation support based on best practices. It also recommends that brief counseling sessions (30 seconds to 3 minutes per consultation) be systematically provided to all tobacco users in all healthcare settings. Similarly, lifestyle advice should be given to patients experiencing infertility before and during their treatment. Smoking cessation helplines, mobile messaging programs, digital tools and approved pharmacological treatments are among the recommended approaches, described in the WHO 2024 clinical guideline on smoking cessation in adults, which is based on the implementation guidelines of one of the provisions (Art. 14) of the WHO Framework Convention on Tobacco Control treaty, FCTC.

«"For all those planning a pregnancy, our message is: quit smoking, improve your health, and improve your reproductive health too.", said Dr. Kerstin Schotte, a physician with the WHO's Tobacco-Free World Initiative[2].

At the level of public policies, the WHO reiterates that the implementation of the measures of the Framework Convention on Tobacco Control (FCTC), including tax and pricing measures, the complete ban on advertising, promotion and sponsorship, plain packaging and protection against exposure to secondhand smoke, is essential to reduce the risks of tobacco, including its effects on reproductive health.

©Generation Without Tobacco

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[1] World Health Organization, Tobacco and infertility, WHO tobacco knowledge summaries, Geneva, 2026. https://doi.org/10.2471/B09819

[2] World Health Organization, «Tobacco smoking may be harming your chances of having a baby», Press release, September 8, 2026, accessed September 10, 2026