GENEVA — Women who smoke cigarettes may face a substantially higher risk of infertility, according to a new World Health Organization review that also finds better outcomes among those who have stopped.
The WHO summary, published on 8 September, draws on research conducted between 2000 and 2026. Across the evidence reviewed, current smokers had an estimated 40% higher risk of infertility than women who did not smoke. Former smokers had about a 25% lower risk than current smokers, suggesting that cessation may recover part of the reproductive advantage.
Those comparisons must remain precise. The former-smoker figure is measured against current smoking, not against never smoking. The review identifies an association across studies; it cannot determine the outcome for an individual or prove that smoking is the only cause when conception takes longer.
Evidence from 21 studies also linked smoking with fewer pregnancies and live births after in-vitro fertilisation, with success in some analyses reduced by roughly half. The WHO reported that secondhand smoke may increase infertility risk and reduce the chance of conception in a given month.
Possible mechanisms include damage to eggs, accelerated loss of ovarian reserve, hormone disruption and effects on the uterus. Smoking can also affect sperm, so responsibility should not be placed entirely on women seeking pregnancy.
The review is strongest for combustible cigarettes. Evidence about vaping, heated-tobacco products and nicotine pouches remains less developed, which is not the same as evidence of safety. People should seek clinically supported cessation options rather than switch products on the assumption that fertility risks disappear.
One in six people of reproductive age experiences infertility, according to WHO estimates. That scale makes stigma particularly harmful. Infertility can arise from female factors, male factors, combined causes or causes that remain unexplained. A smoker should receive practical help, not a moral verdict.
Clinicians can use the findings to ask about tobacco exposure routinely, offer counselling and approved treatment, and include partners in the conversation. Governments can make quitting more achievable through affordable cessation services, smoke-free homes and workplaces, and restrictions on advertising that targets young women.
The most useful message is neither alarm nor certainty. Smoking is a modifiable risk associated with reduced fertility, and stopping appears beneficial. That creates an opportunity for support before fertility treatment begins—and another reason to protect women from exposure they did not choose.
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