The XX Factor

World’s Oldest Baby Delivered by Human Mother!

Last week, the Nobel Prize in medicine was awarded to Robert Edwards, father of in vitro fertilization. It was long-overdue recognition of a tenacious scientist, now ill and ailing, who at one time was a bit of a pariah in the medical field. According to a paper published earlier this year in Human Reproduction , back in 1971, when Edwards and his partner, the gynecologist Patrick Steptoe, were pioneering IVF science, they were turned down by a crucial U.K. funding source because they were seen by the British medical establishment as ill-connected and insufficiently elite, and because Edwards-prescient about the ethical issues IVF would raise-was regarded as too eager to take the debate to the media. The two men persevered with other funds, and the happy result, in 1978, was the birth of Louise Brown. More than 4 million children have been born as a result of that signal achievement.

The ethical consequences continue to astound. This week, we learned that a healthy boy has been born from an IVF embryo that had been frozen for nearly 20 years . This seems to be a record, though it’s always hard to know in a field that is constantly redefining the outer limits of the reproductively possible. (Oldest mother east of the Mississippi gives birth to twins using egg of granddaughter and sperm of Olympic bobsledder! Twelve newborns born at once to U.S. parents using four related surrogates from India! Just kidding about these examples, but it was hard to tell, wasn’t it?) Before now, the longest-frozen working embryo seems to have been 13 years old, meaning the child born was, in a way, already adolescent.

The route that this one took is a little tortured: If I am reading the news accounts correctly, this embryo was created in 1990 as part of a batch. At least one embryo from that batch was transferred at that time into the biological mother, who did have a child-now, presumably, around 20. She later “donated” the leftover frozen embryos, which languished in storage until the current mother, 42, who herself had been getting treatment for a decade, set out to try them, and succeeded in conceiving.

This is not a rare outlier. There are some 500,000 frozen embryos in storage in the United States alone. They are the inevitable byproducts of ordinary IVF, which is now routine and often produces more embryos than can be used in a single procedure. Once treatment is over, many patients find themselves morally paralyzed over the question of what to do with excess embryos or even how to think about them. It’s still difficult to donate frozen embryos for stem-cell research, which is one reason why many people leave them in storage indefinitely. Some, however, take the initiative to locate a prospective parent, often through embryo donation listservs. There is a pro-life outfit, Snowflakes , that sets up so-called embryo adoptions. Of course, if you’re going to pass embryos along to strangers, you have to be OK with the idea of a full sibling to your own children being raised in another family.

Here’s one funny thing about human embryos: They are cheap. At least compared with other babymaking components. Though sperm and especially eggs are sold at high prices in the U.S. reproductive market (the preferred term is “donated,” but there is little charity involved) people are uncomfortable charging money for human embryos, which after all are potentially only nine months away from being human babies, so often there is a relatively low cost involved in embryo adoption or donation or whatever you want to call it. This means that somebody who cannot afford the drugs and egg retrieval and run-up to IVF could get a donated embryo and have the whole shebang done more cheaply. Even more plausibly, for a women whose own eggs are unviable owing to age or anything, really-and this is a substantial group of infertility patients-a donated embryo can be cheaper to obtain than a donated egg. In this case, the whole tends to be less expensive than the part.

The other funny thing about embryos is that unlike human eggs, they turned out to be surprisingly easy to freeze. They can be frozen, and thawed, and frozen again. It seems possible that an embryo could be frozen for 50 years and emerge intact. The resulting complicated multigenerational family relationships seem reminiscent of what can happen when a man fathers children by different women at different times, except that these are full siblings, not half siblings, with years and years between them.

It’s not clear how long this current record will stand. Unlike, say, ice cream sandwiches or frozen chicken breasts, embryos seem to have a very extended shelf-life and do not even seem to get freezer burn. Maybe the next world’s oldest frozen embryo will be 25, 30, or older, when he or she becomes a baby. Thus far, IVF science has exploded our notions about who can be a parent: Single women using donated sperm, single men using surrogates, same-sex partners. Now it has altered our understanding of what it means to be a sibling. For sure, it gives a whole new meaning to the term “generation gap.”