In a new publication reviewing evidence on tobacco use and infertility, WHO said decades of research have linked smoking to infertility in women, while also showing harmful effects on sperm quality and sexual function in men.

WHO Medical Officer with the Tobacco Free Initiative, Dr Kerstin Schotte, urged people planning pregnancies to quit smoking.

WHO defines infertility as the inability to achieve pregnancy after 12 months or more of regular unprotected sexual intercourse. The condition affects about one in six people globally.

The publication also found that quitting smoking can reduce reproductive risks. Women who previously smoked but had stopped were found to have a 25% lower risk of infertility compared with women who continued to smoke.

WHO stressed that infertility is not solely a women’s issue. A review of 44 studies involving more than 60 000 men linked smoking to reproductive dysfunction, including abnormalities in semen and sexual dysfunction.

The evidence also associated smoking among men with erectile dysfunction, ejaculation problems, poor sperm movement and abnormal sperm shape.

Smoking can also affect the success of fertility treatment. Research covering 21 studies found links between cigarette smoking and fewer pregnancies and live births following assisted reproductive procedures, including in vitro fertilisation. WHO said the evidence suggested smoking could reduce the likelihood of successful outcomes by roughly half.

WHO also highlighted potential reproductive risks associated with waterpipe smoking, commonly known as hookah or shisha. Evidence on e-cigarettes, smokeless tobacco and other newer nicotine products remains limited, with further research needed.

Second-hand smoke can also affect fertility, including by reducing the likelihood of conception among women.

WHO has called on healthcare providers to discuss the reproductive risks of tobacco use with people planning pregnancies and provide evidence-based support to help tobacco users quit.

–WHO/ChannelAfrica–