In the summer of 2015, an anti-abortion group released a video showing Planned Parenthood officials discussing what they would charge to provide tissue samples from aborted fetuses for research. While there was nothing illegal about this, the video made the exchange look shady. It engendered outrage among anti-abortion activists, and prompted calls from congressional Republicans to defund Planned Parenthood.
Congress has yet to cut off federal payments to Planned Parenthood (payments that only cover non-abortion services), but the controversy over the use of fetal tissue in medical research has made its way into congressional negotiations over the federal budget. This month, the House of Representatives approved a spending bill that bans the National Institutes of Health from funding any research that uses human fetal tissue obtained from abortions. A parallel Senate bill stops short of a ban, but it does order the NIH to study whether researchers really need fetal tissue from abortions.
Abortion opponents argue that research using fetal tissue is not only morally wrong, but also unnecessary. The anti-abortion Charlotte Lozier Institute quotes a scientist who claims that "fetal tissue from abortions is making a negligible contribution to science." Mainstream scientists disagree. Biochemist Thomas Baldwin, president of the Federation of American Societies for Experimental Biology, in a letter to the House and Senate appropriations committees, wrote that "research using fetal tissue and embryonic stem cells advances scientific knowledge, improves human health, and saves lives."
That scientists use tissue from dead human fetuses no doubt seems creepy to many, and it's natural to ask whether such a controversial source of material is really necessary for medical research. This question might sound familiar, because it was central to the 2001 debate over human embryonic stem cells—a debate that was, back in the months before the 9/11 attacks, considered a significant controversy for George W. Bush's new administration.
At the time, scientists had recently learned how to cultivate human embryonic stem cells, which were seen as medically promising because of the ability of these cells to develop into any cell type in the human body. Because the cells were derived from human embryos or fetal tissue, pro-life groups condemned embryonic stem cell research as morally wrong. They also claimed that alternative types of stem cells, derived from adult tissue, would serve scientists just as well. Scientists and patient advocacy groups pushed back, claiming that work with embryonic stem cells was vital for medical progress. In the end, George Bush tried to split the difference with a partial ban that limited the kinds of embryonic stem cell research that could be paid for with federal dollars.
Human remains, of all ages, have played a critical role in medical research for centuries.
President Barack Obama revoked that ban in 2009, as one of his first acts in office. But, by then, human embryonic stem cells had lost some of their controversial edge, because scientists really had developed an alternative source of cells that reduced the need for material from human embryos. In 2006, researchers had figured out how to create the equivalent of embryonic stem cells from adult tissues, so-called "induced pluripotent stem cells." Researchers now routinely create induced pluripotent stem cells to study the biology of a wide range of diseases and to develop experimental medical treatments.
In light of the scientific progress since 2001, the restrictions now proposed by Congress raise an important question: Is fetal tissue genuinely important for medical research?
The answer is still yes, and here's why: Fetal tissue research plays a relatively small, but critical role in one of the most promising areas of biomedical research, called regenerative medicine. The ultimate goal of regenerative medicine is just what it sounds like: to discover how to regenerate lost or damaged tissue, and thereby develop not just treatments, but cures for some of the most intractable diseases, from diabetes to Parkinson's to paraplegia. A central premise of regenerative medicine is that, to discover how we can regenerate lost motor neurons or insulin-secreting pancreatic cells, it is necessary to understand how such cells develop in the first place. That understanding comes, in part, through studies of embryonic stem cells and fetal tissue.
One new way that scientists study this process of cellular development—and a way in which they hope to grow replacement tissue for medical treatments in the future—is by recreating the essential features of human brains, eyes, lungs, and guts in a petri dish. These lab-grown approximations of human organs are called organoids, and they capture an essential feature of biology: Tissues are not simple collections of similar cells, but rather they are complex three-dimensional arrangements of cells that play many different specialized roles. Organoids reproduce some of that complex organization. Using organoids, scientists are testing cancer drugs, determining the effects of toxins, and studying the development of neurological diseases.
Scientists create organoids from a variety of cellular sources, including induced pluripotent stem cells. To make an organoid, cells are carefully coaxed to go through a process that resembles embryonic development. To check how well this process works, and to understand why it fails in some cases, scientists compare organoids against both fetal and adult tissue samples. For example, a team at the University of Michigan has developed human intestinal organoids, which they use to study disease in both adults and premature infants. In their studies, they determine whether organoids bear the molecular hallmarks of either fetal or adult tissue, and they use the results to develop better organoids.
In the long run, scientists hope to use organoids and induced pluripotent stem cells to engineer tissue replacements in patients suffering from diseases that currently are treated with direct transplants of fetal tissue. Fetal tissue transplants are, in all cases, still experimental, but they have shown some promise as treatments for retinal diseases and Parkinson's disease. The results, however, have been inconsistent, and researchers are searching for the factors that determine whether a treatment is successful. These studies, for the time being, still critically depend on access to fetal tissue.
Aside from regenerative medicine, another major medical application of fetal tissue research is the study of how a fetus is harmed by exposure to infections and toxins during pregnancy. A study published in May used fetal brain tissue to investigate how the Zika virus gains access to the developing human brain, where it can cause catastrophic birth defects. Other studies use fetal tissue to understand how exposure to smoking, alcohol, and other environmental chemicals affect human pre-natal development.
Human remains, of all ages, have played a critical role in medical research for centuries. There are, of course, important ethical questions that medical researchers must consider regarding what human remains are acceptable to use in research. In the United States, abortion is legal, and so is the donation of human tissue for research. Under federal regulations, doctors can't solicit a tissue donation from a woman considering an abortion, but after the choice to abort is made, she may choose to donate the remains to research. Given current U.S. law governing abortions, and the strong scientific case for fetal tissue research, a vote by Congress to restrict fetal tissue research would needlessly hamper science, while having no impact on abortion.