Tobacco smoking may reduce people’s chances of conceiving and harm fertility in both women and men, the World Health Organization (WHO) has warned.
In a knowledge summary published on Tuesday, the WHO said on its website that tobacco use was associated with infertility in women, adverse effects on sperm and sexual function in men, and potentially lower chances of success with some fertility treatments.
The agency also warned that people who do not smoke may face reproductive risks through exposure to second-hand tobacco smoke.
“Smoking may reduce the chances of conceiving for many people worldwide,” the WHO said, citing evidence from decades of research.
Globally, one in six people of reproductive age experiences infertility at some point in their lifetime, according to the WHO.
The agency defines infertility as “the failure to achieve pregnancy after 12 months or more of regular unprotected sex.”
The WHO said a systematic review of studies conducted between 2000 and 2026 found that women who currently smoked tobacco had a 40 per cent higher risk of infertility than non-smokers.
The agency also highlighted evidence suggesting that quitting smoking could improve fertility outcomes.
It said women who had smoked in the past but were no longer smoking had a 25 per cent lower risk of infertility than women who continued to smoke.
The WHO stressed that infertility should not be regarded solely as a women’s health issue.
“A recent review of 44 studies involving more than 60,000 men found that smoking was associated with reproductive dysfunction, including semen abnormalities and sexual dysfunction,” it said.
According to the agency, the evidence showed that men who smoke were more likely to experience erectile dysfunction, ejaculation problems and other reproductive issues, including the absence of sperm in semen, poor sperm motility and abnormal sperm shape.
The potential impact also extends to people seeking medical assistance to conceive.
The WHO said earlier research involving 21 studies found that cigarette smoking was associated with fewer pregnancies and live births following assisted reproduction, including in vitro fertilisation.
The findings suggested that the chances of successful outcomes “may be roughly halved by cigarette smoking.”
The WHO also warned that exposure to second-hand smoke could affect fertility.
“Women exposed to second-hand smoke may have a higher risk of infertility and a lower chance of conceiving each month they try,” the agency said.
However, the WHO said evidence concerning newer tobacco and nicotine products remained limited.
“Evidence is strongest for cigarette smoking, but WHO warns that other tobacco and nicotine products may also pose risks to fertility and require further research,” it said.
The agency said evidence on products including e-cigarettes, waterpipes and smokeless tobacco was still emerging.
The WHO recommended that healthcare providers inform individuals and couples planning pregnancy about the reproductive risks associated with tobacco use and provide evidence-based support to help them quit.
It also recommended that brief cessation advice should be consistently offered to all tobacco users in healthcare settings.
