When I give talks on stem cell research or in in vitro fertilization, people invariably ask, “What should be done with all the frozen embryos?” It is usually asked with a sense of urgency, even desperation, as they reflect on the fate of the hundreds of thousands of human embryos cryopreserved in liquid nitrogen at fertility clinics. The simple answer is that ethically there is very little we can do with the frozen embryos except to keep them frozen for the foreseeable future. No other morally acceptable options seem to exist.

The question of what to do with the frozen embryos, I sometimes remind my audiences, is not in fact the most pressing question we face. A much more urgent issue is how to stop the relentless manufacturing and freezing of new embryos which is occurring each day, with clockwork-like regularity, in every major city in the United States.

The infertility industry has become an embryo mass-production line with virtually no legal oversight or national regulation. Catering to strong parental desires, it is a multibillion dollar business aptly described as the “wild west of infertility.’’ To start to bring this into check, strong laws and regulations like those found in Germany and Italy are urgently needed. In those countries, no more than three embryos may be produced for each infertility treatment, and all three must be implanted into their mother. Extra embryos may not be produced or frozen; as a result, there are essentially no frozen embryos stored in German and Italian fertility clinics.

For those embryos that do end up abandoned in liquid nitrogen, the question often arises: would it be morally permissible to give them up for “embryo adoption,” whereby other couples could implant, gestate and raise them as if they were their own children?

There is ongoing debate among reputable Catholic theologians about this matter, and technically it remains an open question. A recent Vatican document called Dignitas Personae expressed serious moral reservations about the approach, without, however, explicitly condemning it as immoral. But we can easily see reasons why the promotion of embryo adoption would be imprudent. If embryo adoption were to become standard practice in the current, largely unregulated climate of the fertility industry, this could actually stimulate the production of yet more embryos; IVF clinic operators would be able to placate themselves by saying, “We really don’t need to worry about producing extra embryos, because there will always be somebody willing to adopt any that are left over.” It could offer the clinics an excuse to continue and even expand their current immoral practices.

Some have suggested that a morally acceptable solution to the frozen embryo problem might come through applying the principle that “extraordinary” means do not have to be undertaken to prolong human life. They argue that to sustain an embryo’s life in a cryogenic state is to use extraordinary means and this is not required.

In fact, however, the decision to continue cryopreserving an embryo in liquid nitrogen is probably not an instance of using extraordinary means, since the burden and costs involved in taking care of embryonic children in this way are actually minimal. When we have children, we have a duty to clothe, feed, care for, and educate them, all of which costs plenty of money. When our children are frozen, we don’t needt to clothe, feed, or educate them; our care for them can only be expressed by paying the bill each month to replenish the liquid nitrogen in their storage tanks. This way of caring for our children is obviously unusual, but it does not seem morally extraordinary in terms of achieving the desired end of safeguarding their physical integrity.

In my opinion, parents have an obligation to care for their children in this way until some other option becomes available in the future (maybe a sophisticated “embryo incubator” or “artificial womb” of some kind), or until there is a reasonable certainty that they have died on their own from decay or “freezer burn,” which may occur whenever frozen embryos are stored for extended periods. Perhaps after a few hundred years, all the stored embryos would have died on their own, and they could finally be thawed and given a decent burial. This approach would not involve us in the direct moral agency of ending their lives by withdrawing their life-sustaining liquid nitrogen.

Frozen embryos, clearly, can never be donated to science. Such a decision would amount to handing over not cadavers, but living human beings, for dismemberment at the hands of stem cell researchers. This would always be a radical failure in the parents’ duty to protect and care for their offspring.

These considerations indicate the difficulty of answering the question about the disposition of frozen human embryos. We are reminded how sinful choices have consequences, and how the original decision to violate the moral law by doing IVF invariably has grievous repercussions, including the kinds of quandaries considered here, for which no moral resolution is apparent.

Rev. Tadeusz Pacholczyk, Ph.D. earned his doctorate in neuroscience from Yale and did post-doctoral work at Harvard. He is a priest of the diocese of Fall River, and serves as the Director of Education at The National Catholic Bioethics Center in Philadelphia. See www.ncbcenter.org