Across Britain on Thursday, medical workers in the country's 73 licensed infertility clinics will for the first time be subjected to an unusual law requiring that unclaimed frozen human embryos be destroyed after five years.
More than 3,000 of the embryos, each no larger than the dot at the end of this sentence, are expected to be thawed and "allowed to perish," as authorities put it. The Catholic Church has protested, with a Vatican newspaper calling the action a "prenatal massacre" and urging that women volunteers bring the "orphan" embryos to term in "prenatal adoptions."
The looming British deadline, which has sparked sensational media coverage there, highlights basic dilemmas associated with freezing human embryos, the ultimate suspended animation. Those typically four-celled specks may remain viable for decades, scientists say, and even the most liberal ethicists are disturbed by the prospect of freezers chockablock with potential people, who might be born long after their genetic parents are gone.
Moreover, the clamor in Britain highlights what many researchers say is a lax approach to producing test-tube babies in the United States. "We don't have any clear law over what to do with a frozen embryo that isn't claimed," said Albert Jonsen, an ethicist at the University of Washington and chairman of the National Advisory Board on Ethics in Reproduction.
But the leading U.S. professional group, the American Society for Reproductive Medicine, is for the first time drawing up guidelines for dealing with "abandoned embryos." It has proposed that clinics be allowed to destroy frozen embryos after five years if the donor couple have disappeared without leaving specific instructions to store the tissues longer.
"We don't like having large numbers [of embryos] in the bank," said the society's president, Dr. Mary Hammond, a fertility specialist at the North Carolina Center for Reproductive Medicine, a private clinic in Raleigh. "It's a tremendous responsibility." The abandoned embryos in the U.S. haven't been counted, Hammond said, but other researchers have estimated that the number is as high as 20,000.
The society's members are split over the need for federal regulation like that in Britain, she said. Some welcome it, arguing that it would ease the burden of deciding what to do; currently, many clinics fear being sued if they destroy stored tissues without the donors' permission. But others resist such oversight, saying it would interfere with the doctor-patient relationship.
The technique of in vitro fertilization--which involves surgically removing eggs and fertilizing them with sperm in a test tube--was developed in the 1970s and primarily benefits women who produce healthy eggs but cannot become pregnant. By freezing the embryos, first done in the early 1980s, a physician can keep trying to implant one without having to repeat the onerous egg extraction.
Still, a frozen embryo results in a pregnancy in only 10% to 15% of implantation attempts, compared with 25% to 40% for a fresh embryo, Hammond said.
Frozen embryos are abandoned for a variety of reasons, researchers say. Couples who succeed at pregnancy may no longer need stockpiled embryos. Some couples fail to have a child and give up. Others split up, or simply lose touch with clinics.
The impending destruction of frozen embryos in Britain is an unprecedented event brought on by a coincidence: The law limiting frozen embryo storage to exactly five years was enacted Aug. 1, 1991, when more than 6,000 frozen embryos were already in storage.
Britain's Human Fertilisation and Embryology Authority, said to be the world's only national agency solely devoted to enforcing test-tube baby regulations, estimates that 3,300 frozen embryos, from about 900 couples, are slated for destruction.
Of those couples, about 650 have disappeared or otherwise lost contact with their clinics. Many were not British subjects and only visited the country to undergo the procedure. But 250 couples have not responded to registered letters warning them of the Aug. 1 deadline. "We feel that a lot of people are just not able to make a decision about embryos in storage . . . and are leaving it to the law," said agency spokeswoman Jennifer Woodside.
Under the British law, couples who ask in writing for an extension can have an additional five years. An exception is also made for a woman who develops cancer and faces therapy that could harm her ovaries, damaging her eggs; she could generate numerous embryos and freeze them until she is 55.
Rather than having their frozen embryos destroyed, British couples could give them to researchers for study or donate them to couples incapable of creating a fertilized egg themselves. In any event, written permission must be obtained from sperm and egg donors alike.