Taking hayfever tablets could put men at higher risk of infertility, a study claims.

Scientists said the findings suggest men should limit the use of over-the-counter antihistamines when trying for a family.

Around one in six couples struggle to conceive - with male infertility linked to at least a third of cases.

Millions of Britons take antihistamine tablets, to treat symptoms of allergies such as hayfever.

Up to one third of adults are estimated to suffer such allergeies, which can cause a runny or blocked nose, itchy eyes, wheezing, sneezing or skin rashes.

The drugs work by controlling levels of histamine, a molecule produced by the immune system in response to a potential threat.