A Controversy: How long should human embryos grow in a lab?

Suppose that you were a firefighter. You are inside a burning building, trying to rescue the inhabitants. There are two rooms. One of them has a crying toddler inside it, and the other has a culture of embryonic cells. You only have time to save one of them from the fire. Which option would you choose?

MV Teacher Andrew Goldenkranz would choose the room with the toddler. The toddler has a certain future in front of her, while it is doubtful that those cells would actually be implanted and cared for well enough to survive to become human beings.

The question of whether to allow scientists to study embryos in vitro (in lab) for a longer amount of time is just as hard to answer. It would certainly lead to “huge discoveries,” as Magdalena Zernicka-Goetz told RT News. It would also be a big help in figuring out what happens in miscarriages. But it involves letting embryos live past implantation stage in vitro, which means after the experiment is done, they must be discarded. Should it be allowed or not?

Taking a step back, it must be noted that this was never a question until a year ago. Previously, when scientists tried to grow an embryo in vitro, it would either die or have to be implanted into a womb by day seven or at most, day nine. But last year, thanks to a new method outlined in the magazine Nature, scientists have broken that record. Two separate studies conducted by US and UK scientists succeeded in growing embryos in lab for 13 days, stopping the process only to stay within the legal limit of 14.


The Benefits

An extension would be incredibly beneficial. As Zernicka-Goetz told RT News, it would help scientists gain a deeper understanding of the “critical stages” of embryo development.” For instance, both teams found that there was a “mystery cell structure” that appeared and disappeared within two days. This suggested that there was an unknown biological process was occurring. Having more time would help them study it better. Azim Surani, from The Gurdon Institute in Cambridge, favors an extension: “In my opinion, there has been a case to allow culture beyond 14 days even before these papers appeared.”

The scientific benefits of an extension are undeniable and unpredictable. As Brinvalou told RT News, trying to predict the discoveries is like asking, “If I look at new sets of Hubble Space Telescope pictures that I haven’t seen yet, what will I learn from them?” It is impossible to know until they are actually looked at. From all this, it may seem that the scientific community as a whole is itching for change.


The Other Side

But that conclusion presents only half of the story. It is true that scientists feel that there may be a case for an extension, but they believe that it is an issue for the future, not the present. While Zernicka-Goetz also asserted that just a few extra days would lead to “huge discoveries,” she nevertheless said that she would not lobby to overturn existing limitations. Many scientists feel the gravity of the potential effects of an extension: As unpredictable as the benefits of an extension are, so are the consequences. As Prof Robin Lovell-Badge, Group Leader, from The Francis Crick Institute, told Telegraph Magazine: Would extending the 14 day limit result in opening a “Pandora’s box” or “a treasure chest of valuable information?” There are as many risks as benefits to this venture.

Along with technical issues which keep scientists from being certain that they would be able to deal with the embryo’s complex and growing nutritional needs come ethical concerns. The 14-day limit was set because it is considered to be a definite marker of individuality: twins cannot separate after this stage. Also, this is right before the neural tube, the first developmental form of a brain, starts to form. A change to the deadline would also prompt a change to these definitions of a living individual.


Arguments For An Extension

But these definitions, according to Goldenkranz, are too arbitrary. Why decide on the start of the neural tube? We could say that the limit is when the baby’s heart starts beating, or even when the embryo is conceived. There are many ways, and each of them is just as valid as the others. The most definite, in Goldenkranz’s opinion, is the earliest date at which the baby can survive out of the womb on artificial support. An extension is not a problem as long as it stays under that point.

Goldenkranz offered another argument in favor of the extension, and embryo research in general. The embryos used for such research are usually remnants of an artificial implantation procedure that would be discarded anyway, if some use wasn’t found for them. When eggs are fertilized in vitro (due to some complication which prevents it from happening naturally), 8 or 10 are fertilized all at once. In the end, only one or two will be artificially implanted in the uterus of the mother. But what to do with the rest? They can either be used for research, or be discarded directly. According to Goldenkranz, it is certainly better to use them for a beneficial purpose than simply wasting them.

The Nuffield Council of Bioethics, the UK body which decides on contentious scientific research, “has already stated that it will independently review the current experimental limits.” Many believe that a revision of the law is long due. Even 20 years ago, when this law was formed, there were people who argued that the limit should be 21 and not 14. An article in Nature has already put pressure on the law.


The Decision

Lowell-Badge responds to these pressures with an assertion that many scientists and nonscientists alike hold dear: “This is not a question to be left to scientists alone.” Zernicka-Goetz expressed the same idea, saying that it is not scientists’ decision whether embryos should be allowed to cultivate for longer.  The scientific community is united in its belief that the issue should be discussed upon by all.

But even that approach has its limitations. As Goldenkranz said, for a non-scientist to staunchly be for or against a scientific measure is similar to when someone says, “Well, I’m not an expert on this topic, but I still want to express my opinion on it.” The preamble itself indicates such an opinion may not be fully informed, since it is not that of an expert. Scientists and nonscientists alike must make sure that any opinions are fully informed. Good communication is the key.

After making sure to communicate and fully inform, we can all come to an agreement and a decision. We may decide to favor the potential benefits of an extension over the problems it poses and extend the law. We may take the ultimate route of caution by deciding to let the law be as is. Or we may take a middle course and decide to deal with an extension sometime in the future, but not just yet.

Cover Image – BioEdge