The study has been published in the latest online edition of the American Journal of Epidemiology. The Telethon Institute for Child Health Research is affiliated with The University of Western Australia.
Report author Dr Elizabeth Milne said the study looked at the association between parental smoking and the most common form of childhood cancer, Acute Lymphoblastic Leukaemia (ALL) which affects one in 2000 children in their lifetime.
“The results of our study indicate that the risk of ALL could be increased by 35% when fathers smoked more than 15 cigarettes a day around the time of conception,” Dr Milne said.
“This fits with what we know about how tobacco smoke can damage the DNA in sperm, but these sperm are still able to fertilise an ovum.”
Dr Milne said they found no increase for those who had previously smoked, suggesting that sperm with normal DNA may be produced after smoking is ceased.
“While women are often informed of the dangers to their unborn baby of smoking during pregnancy, this study shows that we also need to direct that message to potential fathers,” she said.
Dr Milne urged caution in drawing a link in individual cases or laying blame.
“The causes of childhood leukaemia are likely to involve many interacting factors of which only one is cigarette smoke.
“However we do think it’s important that potential fathers know the potential damage that could be caused to their sperm and have the opportunity to reduce that risk by stopping smoking.”