The World Health Organisation says new evidence shows that smoking may reduce the chances of conceiving, linking tobacco use to infertility, reproductive dysfunction and poorer outcomes from some fertility treatments.

In a statement issued on Tuesday, the global health body said the knowledge summary highlighted evidence that smoking could harm women’s reproductive health, affect sperm and sexual function in men, and reduce fertility treatment success.

The publication also warned that people did not have to smoke themselves to face reproductive risks, noting that exposure to second-hand tobacco smoke might also affect fertility and reproductive outcomes.

According to WHO, about one in six people of reproductive age globally experience infertility at some point in their lifetime, defined as the failure to achieve pregnancy after 12 months of regular unprotected sex.

“A systematic review of studies conducted between 2000 and 2026 found that women who currently smoke tobacco had a 40 per cent higher risk of infertility than women who do not smoke,” it said.

The statement added that evidence suggested quitting smoking could make a meaningful difference, with women who previously smoked having a lower risk of infertility than those who continued smoking.

WHO restated that infertility was not solely a women’s health issue, citing significant evidence linking smoking among men with reproductive dysfunction and abnormalities in semen quality.

“A review of 44 studies involving more than 60,000 men found smoking was associated with erectile dysfunction, ejaculation problems and abnormalities affecting sperm. These abnormalities included absence of sperm in semen, poor sperm movement and abnormal sperm shape, all of which can interfere with reproductive potential,” it said.

The statement noted that smoking might also reduce the effectiveness of fertility treatment, with earlier research linking cigarette use to fewer pregnancies and live births following assisted reproduction.

“Evidence from 21 studies suggested that cigarette smoking could roughly halve the chances of successful outcomes from assisted reproductive procedures such as in-vitro fertilisation,” it said.

WHO further stated that second-hand tobacco smoke might increase infertility risks, particularly among women, who might face a lower chance of conceiving during each menstrual cycle.

It noted that evidence on newer tobacco and nicotine products, including e-cigarettes, waterpipes and smokeless tobacco, was still emerging, although waterpipe smoking might also affect male fertility.

According to the statement, WHO recommends that healthcare providers discuss tobacco-related reproductive risks with people planning pregnancy and consistently offer evidence-based support to help tobacco users quit.

(NAN)