Calling all men – Britain's future depends on your loins.
For it's been revealed that the UK is facing a 'major' sperm shortage – and some clinics are now relying on imported sperm to meet demands.
BFS chairman, Dr Allan Pacey told the BBC he was concerned women could be subjected to more invasive procedures if lower quality sperm is used, citing possible examples of sperm being accepted that would be suitable only for injecting into an egg, known as intra-cytoplasmic sperm injection.
He said: "That is putting the woman through more procedures, in terms of eggs being collected, than would be done if sperm of higher quality was collected and she could be treated with a simple insemination.
"My worry is clinics may be tempted to bend the rules, I have no evidence that they are, but I think when we have a national sperm shortage they're the kind of things we need to be looking for and warding against."
The decline in the number of sperm donors is thought to be attributed to the removal of the right to anonymity in 2005.
One in four donated sperm samples are now from abroad – a sharp increase from one in ten in 2005, according to figures from the fertility regulator, the Human Fertilisation and Embryology Authority (HFEA).
According to Dr Pacey, this limits patient choice and increases waiting times, which in turn could increase the chances of risky practices such as DIY insemination from an unregistered donor.
Dr Pacey added: "We do still have a major sperm shortage in the UK.
"The worry is clinics might decide to change the quality of sperm they are willing to accept in order to get donors through the door and I think that's a very dangerous road to go down."
A HFEA spokesperson said: "We expect our clinics to use only donor sperm of a quality that will ensure the best outcome for the patient, and under our code of practice clinics are required to fully inform patients of the different treatment options available to them."