Children born from donated sperm could soon be given the right to trace their biological fathers.
Children could win the right to trace their biological fathers
The government is expected to make an announcement soon on its public consultation on donor anonymity.
Some fertility experts fear it will include new legislation allowing children of sperm donation to trace their biological fathers.
They warn the move could scare off potential donors when there is already a shortage.
Around 1,000 children are born in the UK every year from artificial insemination.
The sperm donors, three quarters of which are students, remain anonymous.
Dr Paul Serhal, of University College London, said the lifting of that anonymity could deter donors.
He told BBC Radio Five Live: "This would certainly impact on the number of potential sperm donors and would also deny a patient the basic right to having treatment for sperm donation on an anonymous basis."
He also said it may push patients seeking sperm donation to go abroad "where the guidelines for screening may not be as rigorous as here".
While Dr Serhal believed in the basic right of children to know the identity of their father, he said it was also important to consider the right of the would-be parent to choose whether to tell their children about sperm donation.
He advocated a two-tier system, where donors can choose to reveal their identity or remain anonymous.
In Sweden, the onus is on the parents to tell their children they were conceived from sperm donation.
Dr Serhal said a recent survey in Sweden showed that the majority of parents did not opt to tell their children - "so it is back-firing, because it is pushing parents to be more secretive
about sperm donation with their children".
Those supporting the change in the law say many children suffer from never knowing the identity of their fathers.