World Health Organization (WHO) has warned that smoking is very likely to make it harder for people to have a baby, with new evidence highlighting the significant impact of tobacco use on reproductive health among both women and men.

The UN Health Agency revealed that women who smoke face a 40% higher risk of infertility compared with non-smokers, reinforcing decades of evidence linking tobacco use to difficulties in conceiving.

According to WHO, infertility affects approximately one in six people globally, making reproductive health a significant public health concern and increasing the importance of identifying preventable factors that can undermine the ability to conceive.

WHO’s latest publication brings together evidence on the relationship between tobacco smoking and infertility, highlighting the consequences of smoking not only for women trying to become pregnant but also for male reproductive health.

Dr Kerstin Schotte, Medical Officer with WHO’s Tobacco Free Initiative, stated that “for all people who plan pregnancies, our message is, Stop smoking, improve your health, improve your reproductive health as well.”

WHO noted that the available evidence shows that tobacco use is associated with infertility in women while also affecting sperm quality and sexual function in men.

The findings challenge the perception that infertility is predominantly a women’s health issue, with WHO stressing that reproductive difficulties can involve factors affecting either partner.

Furthermore, the agency’s assessment points to the potential reproductive consequences of exposure to tobacco smoke among people who do not smoke themselves.

Second-hand smoke, WHO indicated, may also affect fertility, meaning that exposure to tobacco can present reproductive risks beyond those faced by active smokers.

The findings therefore place smoking cessation within the broader context of reproductive health, particularly for individuals and couples who are planning to have children.

WHO also highlighted evidence suggesting that stopping smoking can improve reproductive prospects. Women who smoked in the past but have since quit may have a 25% lower risk of infertility than women who continue to smoke tobacco.

Earlier research reviewed by WHO found that cigarette smoking is associated with fewer pregnancies and live births following assisted reproduction, including in vitro fertilisation (IVF).

The evidence suggests that cigarette smoking could reduce the chances of successful fertility-treatment outcomes by roughly half, adding another dimension to the reproductive health consequences associated with tobacco use.

WHO’s warning extends beyond conventional cigarettes. The agency also identified potential reproductive risks associated with waterpipe smoking, commonly known as hookah or shisha, particularly in relation to male fertility.

While evidence concerning newer products remains less conclusive, WHO mentioned that research on e-cigarettes, waterpipes, smokeless tobacco and other tobacco and nicotine products is still emerging.

The agency stressed that the uncertainty surrounding some newer products should not be interpreted as proof that they are harmless to reproductive health, noting the need for further research into their potential effects.

Tobacco exposure affects fertility through many pathways, thus WHO is advising healthcare providers to include reproductive health risks in interactions with women and couples seeking parenthood.

Not Only a Women’s Issue

Meanwhile, WHO’s assessment places particular emphasis on male reproductive health, warning that smoking can contribute to a range of problems that may affect a man’s ability to father a child.

A review of 44 studies involving more than 60,000 men found that smoking was associated with reproductive dysfunction, including abnormalities in semen and sexual dysfunction.

The evidence showed that men who smoke were more likely to experience erectile dysfunction and ejaculation problems, while also facing reproductive abnormalities affecting sperm.

Among the problems identified were the absence of sperm in semen, poor sperm motility and abnormal sperm shape.

These findings are significant because successful conception depends on reproductive health in both partners, meaning that efforts to address infertility cannot focus exclusively on women.

WHO’s evidence indicates that tobacco exposure can affect male fertility through both sexual dysfunction and changes in the characteristics and quality of sperm.

The agency therefore recommends that reproductive-health discussions involving people planning pregnancy should take tobacco use into account regardless of whether the individual seeking advice is male or female.

The findings also highlight the importance of considering the reproductive health of couples rather than treating infertility as a problem belonging to one partner.

WHO’s findings suggest that reducing tobacco exposure should therefore form part of broader efforts to improve the health of people preparing for pregnancy.