Live birth from an embryo stored for decades raises ethical questions…again.

October 13, 2010Carole 4 Comments »

IVF made big news again this week when numerous news outlets picked up the Fertility and Sterility journal article published September 30, 2010, reporting a live birth in May from a cryopreserved embryo that had been frozen nearly two decades ago. The embryo was stored for 19 years and 7 months. The earliest record for embryo storage before a live birth had been 13 years.

The embryo whose thaw resulting in the May birth was one of nine fertilized eggs (zygotes) that were frozen in the original IVF cycle in 1990. In 1990, four of the nine zygotes were thawed, two survived and were transferred to the original couple, resulting in the birth of a child who is now nearly twenty. The originating couple decided to release their embryos for adoption sixteen years ago and the embryos remained “unadopted”  until a match with a recipient couple was made in August 2009.

Of the five embryos thawed in August, two survived and grew into cleavage stage embryos of good quality and were transferred on day 3 to the recipient couple who had been going through fertility treatments themselves for a decade without success. They had a baby boy in May. Their newborn is the biological brother to a young adult born almost twenty years earlier to the originating couple.

As usual, I expect a flurry of renewed ethical debates to follow this news, although it really changes nothing. Scientists have long known that embryos can be stored much longer than makes sense based on our social and cultural expectations of an individuals life cycle.  There is no theoretical limit to how long embryos could be frozen in liquid nitrogen because no metabolic activity is occurring at these ultra low temperatures and the embryos are literally in suspended animation.  If not shielded from background radiation, the embryo will eventually deteriorate and become non-viable due to a break down the integrity of the embryo’s DNA. Would this take 50 years?, a hundred years?, a thousand years? I don’t know.

Sometimes professional opinions expressed about a “shorter shelf life” of embryos frozen in years past are  due to concerns that freezing procedures where not always as good as they could have been.  Through hard experience, clinics have realized that some embryos are less likely to be viable due to their stage at freezing, quality at freezing or technical proficiency at the time of freezing. These factors, and not some known shelf-life of embryos in liquid nitrogen are responsible for low expectations clinics may have for some of their frozen embryos. Also, remember that surviving thaw is one thing and creating a pregnancy is another. Just as with fresh embryos, some frozen embryos will never be able to make a baby due to problems within the embryo.

Zygotes freeze particularly well with the slow freeze protocols used twenty years ago so the survival and viability of at least one of these five embryos was not particularly surprising. Note that not all embryos survived and not all of the thawed embryos created a pregnancy either in the August cycle or the cycle from twenty years ago.  Only one of the five donated embryos resulted in a pregnancy and live birth. Sometimes when the fate of stored embryos is discussed, it is assumed that each and every stored embryo will produce a child, if only given the chance. This is not true.

The problem isn’t that science can store embryos indefinitely, the problem is that we are left with extremely hard ethical choices (individually and as a society) based on widely divergent personal beliefs. An embryo stored today could be thawed fifty years or a hundred years from now and might result in the birth of a child whose first order biological relatives would likely all be dead or at least in advanced old age. Is this fair to the resulting child? Is it better to limit storage times and allow frozen embryos to be thawed and transferred in a socially relevant time frame to their conception? Great Britain has relied on legal regulation of ART to grapple with the problem of excess embryos.

When regulation collides with personal choice. The Human Fertilisation and Embryo Authority (HFEA) of Britain regulates assisted reproductive technology (ART) in Great Britain since it’s inception in 1991. HFEA licenses and inspects IVF centers and generally provide federal oversight for IVF performed in Great Britain. With this oversight comes controversy. In August 1996,  a five year limit on embryo storage was reached for abandoned embryos that were stored in 1991. As many as 650 couples who created and stored these embryos failed to make contact with the clinic and after repeated attempts to reach them without success, approximately 3000 embryos were deemed abandoned and destroyed, setting a precedent for embryo destruction of abandoned embryos after five years. In August of this year, Great Britain extended the storage period to ten years and is considering  allowing storage for 55 years. It is unclear if or under what circumstances the ten year limit can be extended.

This article eloquently narrates the embryo storage dilemma through personal  stories of couples  who must make difficult decisions about excess embryos in storage. Interestingly, when the laws in Britain recently changed to allow donor-conceived children to contact the donors when they turn 18, the number of couples choosing embryo donation fell sharply. Most couples, both here and Britain still choose to discard their embryos without use.

Some of the thorny questions that arise from storage of excess embryos:

Who decides what happens to the embryos that a couple create? The couple? Their doctor? The government? The most vocal political activists?

What time frame should couples have to make a decision? Indefinitely? Within a biologically relevant time period (e.g. within a woman’s reproductive life span)? Within a socially relevant time period (e.g. first order relatives still living)? Can embryos be willed as property to descendants?

Are embryos property or cells with potential or people? Who gets to decide? Each couple or the society or government they live in? Does your answer differ depending on whether you are personally affected?Does your answer differ depending on who is paying to create or store the embryos?- private or public funds?

Once again, the science turns out to be the easy part.

© 2010, Carole. All rights reserved.

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