A leading supermarket chain is to give paid leave to male and female staff having fertility treatment.

Women working for Asda will be entitled to up to five days of salaried leave to cover time in hospital for IVF treatment and recuperation while men will have up to one and a half days to support their partner. The offer, one of the first by a big employer, applies to all Asda's 129,000 staff regardless of length of service or whether they are full or part-time. It will cover up to three cycles of IVF treatment.

Asda said the request for paid leave came from monthly "colleague circles" in which shop-floor workers discuss the changes they would like made with the chief executive.

David Smith, Asda's head of human resources, said: "There was a big increase in the number of colleagues asking for support through their fertility treatment. Our colleagues didn't want to rely on calling in sick to cope with such an important procedure so they asked for our help."

The aim is to make the treatment less stressful for employees, which will improve the likelihood of success.

The initiative could be adopted by Asda's American parent company, Walmart.

Infertility groups welcomed the supermarket's initiative. Child, an infertility support group, said not enough employers recognised the emotional impact of IVF treatment. "I would like to see more companies take Asda's lead, whether it is paid leave or not. Infertility is an illness and it needs to be treated as such," said Sheena Young, Child's director of business development. Mark Hamilton, treasurer of the British Fertility Society, said: "Some patients are lucky to have understanding bosses, and, for them, getting time off is not a problem. But this isn't the case for all patients and the difficulties they encounter compound their fertility problems."

The National Institute of Clinical Excellence (Nice) recommended last week that women under the age of 40 should, in certain circumstances, receive free fertility treatment. One in six couples is estimated to be infertile, and there are 27,000 attempts at IVF treatment each year. The typical cost of each attempt is £2,500.