In a landmark ruling on Wednesday, a high court judge in London rejected a challenge by Natallie Evans and Lorraine Hadley to a law which states that embryos must be destroyed unless both parties consent to storage and use.
Evans, 31, and Hadley, 38, both underwent in vitro fertilisation (IVF) treatment with their respective partners and have a number of embryos in storage.
The couples have now separated and the partners have withdrawn consent for the use of the embryos.
The Human Fertilisation and Embryology Act states that, unless both parties consent to storage and use, the embryos must be destroyed.
Justice Nicholas Peter Wall heard in June and July that it was Evans' last chance to have children of her own, because her ovaries were removed after they were found to contain pre-cancerous cells.
She met her former partner, Howard Johnston, in 1999 and they lived together until last year when he ended the relationship.
Evans claims that Johnston led her to believe that he would never stop her using the embryos, as he knew how important having a child was to her.
"While empathising with the situation of both women, the BMA feels it would be a very dangerous step to change the rules on consent retrospectively"
chairman, BMA ethics committee
Hadley was married to husband Wayne until he left her for another woman in 2000. When they separated, Hadley agreed the embryos should remain in storage, but later changed his mind.
In handing down his decision, Wall - a specialist in English family law - expressed his "considerable sympathy for all four of the adults in the dilemma which they faced in these two cases".
He said it would be easy to criticise Johnston and Hadley, but added: "Such criticisms would, in my judgment, be unfair."
Though Wall has refused the two women permission to appeal against his ruling, they can apply directly to the Court of Appeal to see if that refusal can be overturned.
The British Medical Association (BMA), which represents the majority of Britain's practising physicians, said it believed the right decision had been made.
"While empathising with the situation of both women, the BMA feels it would be a very dangerous step to change the rules on consent retrospectively," said Michael Wilks, chairman of the BMA's ethics committee.
"The couples clearly agreed that the embryos could only be used with the go-ahead of both parties," he said.
"Consent was given on the basis that it could be withdrawn or varied at any time up until the embryos were used in treatment. The principle of valid consent is an important one that must be upheld."
Annually, 45,000 couples seek IVF treatment in Britain, and 27,000 couples a year receive it, but mostly in the private sector where it costs 2,500 to 3,000 pounds ($4,155) per cycle of treatment.