Ball is put back in the men's court

12.03.40: THE GOVERNMENT plans to make contraception a male responsibility.

Teenage boys will be offered the chance to have specially prepared genes injected into their testicles, to make them temporarily infertile. When they want to father a baby, they take a drug that turns off those genes.

'Lots of boys already have gene-altering injections to reduce the chances of their children having genetic diseases,' says Professor Tom Royston, the chief health officer. 'This only expands that programme.'

The genes modify the sperm, fooling the ovary into putting up an electromagnetic barrier.

'The barrier normally goes up when one sperm has got in,' says Royston. 'The modified sperm makes the ovary think it has already been fertilised.'

In the past, one of the problems with male contraception was that it was often difficult to determine if men were really using it or lying. Under the new scheme, potential mates will be able to access an online database in seconds to check if their partner is listed as one of those who have had the operation.

'Targeting the male side of contraception is much easier because the system is far simpler,' says Royston. JB