A new federal policy tied to anti-abortion politics will hamper potentially groundbreaking work
Aitor Aguirre, a biomedical engineer at Michigan State University, has held a heart from a human fetus in his hands.
Aguirre studies congenital heart disease, which affects 1% of babies born in the United States every year, making it the most common type of birth defect. Though he usually conducts experiments on human stem cells and in mice, he sometimes needs fetal heart tissue to confirm his findings. Aguirre knows where that comes from: elective abortions. And he knows that he’s only able to get this tissue after someone has made a deeply personal and possibly difficult decision.
“Working with fetal tissue is not the easiest thing in the world,” he says. “I don’t think anyone does this kind of science for fun.”
Fetal tissue, which refers to any tissue or organ obtained from a fetus, has been used in medical research in the United States since the 1930s. It’s used to study birth defects, HIV, vision problems, brain disorders, the Zika virus, and more. Cell lines grown from fetal tissue were vital in the production of the first polio vaccine.
“We use fetal tissue if we can obtain it. In reality, it’s the only way that we can validate whether our findings are real or not.”
But almost as long as it has been part of medical science, fetal tissue research has been controversial in the United States because of its connection to abortion and to Planned Parenthood, which along with other clinics, supplies such tissue to biotech companies or tissue banks that in turn provide it to researchers. Under a 1993 law, these providers cannot profit from the sale of fetal tissue itself, but they can charge for transporting, processing, or storing it.
Now the work of scientists like Aguirre could be upended by a new Trump administration policy, announced last month by the U.S. Department of Health and Human Services (HHS), which ends some federally funded research that involves fetal tissue from elective abortions and puts stringent restrictions on the rest. The new policy eliminates all research at the National Institutes of Health (NIH) — the chief federal body on medical research — that uses fetal tissue from elective abortions. NIH scientists can use up the material they currently have, but are not allowed to acquire any new tissue. NIH-funded research at universities and other organizations that involves fetal tissue from elective abortions will also come under additional scrutiny. Investigators proposing new grants or seeking grant renewals that use this tissue will be subject to additional oversight. That process will include an ethics advisory board that will review each grant proposal and make recommendations about whether NIH should fund them. The HHS secretary — currently Trump-appointee Alex Azar — will have final say in whether projects get funding.
The move pleased the anti-abortion groups that have been staunch in their support of President Donald Trump. “Embryos, or aborted fetuses in this case, are human beings and we should protect their dignity,” says Paige Comstock Cunningham, executive director of the Center for Bioethics and Human Dignity, a Christian research center based at Trinity International University in Illinois.
Many abortion opponents, like Cunningham, say they are not opposed to all research uses of fetal tissue — just when it is obtained from elective abortions.
But scientists say that the new policy puts vital medical work at jeopardy and could lead to a brain drain of researchers leaving the U.S. to pursue their projects elsewhere. Federally-funded research that involves fetal tissue is already strictly regulated. For instance, a pregnant woman seeking an abortion must give written permission when donating fetal tissue to research, and that consent process must happen at a separate time after the woman consents to the abortion procedure. Consent forms must clearly state what the tissue will be used for, and researchers may have no contact with donors. Universities also have their own institutional review boards, which evaluate proposed research studies to ensure that they’re ethical.
Scientists say an extra layer of review on top of existing laws will be redundant and could slow down vital medical research, especially since the new ethical advisory board will have up to six months to make funding recommendations. Each ethics board will have 14 to 20 people from various backgrounds on it, including at least one attorney, one ethicist, one physician, and one theologian. Between one-third and one-half of the board must be scientists.
As the biggest public funder of biomedical research in the world, NIH currently supports around 200 projects that involve fetal tissue, and spent an estimated $115 million on fetal tissue research in 2018 out of a total budget of $26.9 billion. Any change in its funding methodology will have a major impact on medical research in the U.S.
“We have no idea what’s going to happen,” says Larry Goldstein, a professor of cellular and molecular medicine at the University of California, San Diego. “If it’s a lopsided board that opposes fetal tissue research, it could be disastrous.”
Cells taken from fetal tissue are valuable to researchers because they grow more rapidly and are more flexible than adult cells, and they allow scientists to study early biological development, including organ formation. For example, Aguirre studies the origins of congenital heart disease. There are some genetic drivers of these heart defects, but in many instances, the causes are unknown. Scientists suspect that environmental factors like pollutants and diet are at play.
Since perfectly healthy women and men with no history of congenital heart disease can have children with congenital heart problems, it’s difficult to predict which babies will have it. Aguirre’s team is trying to find clues that could point to which newborns will be most at risk. His lab uses induced pluripotent stem cells — adult cells that have been reprogrammed to an embryonic-like state — to recreate early human heart development in a petri dish. He also uses mice to study how the fetal heart develops during pregnancy.
But these models can only go so far. “There is a moment when you discover something in human stem cells, and in the mouse, where you need to validate whether it’s something that really happens in a human embryo or not,” Aguirre says. “In those cases, we use fetal tissue if we can obtain it. In reality, it’s the only way that we can validate whether our findings are real or not.”
These types of validation studies account for much of the need for fetal tissue in scientific research. It’s also used to study brain and eye development and to test the toxicity of drugs used by pregnant women. Other scientists use fetal tissue to make so-called humanized mice so they can study the body’s response to HIV and other viruses and test potential therapies. From fetal tissue, they derive stem cells, which are then implanted into mice without a working immune system. These mice then express some human genes and are able to produce human immune cells.
Alexander Ploss, a molecular biologist at Princeton University, employs these mice to study human viruses like hepatitis, dengue, and yellow fever because most animals used in lab research aren’t affected by these pathogens. Ploss and his team take blood-forming stem cells from the fetal liver to create their mouse models. “Outside a petri dish, you cannot easily study these infections in animal models,” he says. Ploss’ work is funded by NIH, so his research could be affected by the new ethics board.
Though the new policy will only directly affect 12 funded studies within NIH, Dr. Elizabeth Ross, director of the Center for Neurogenetics at Weill Cornell Medicine in New York, argues that even a handful of halted experiments could hinder further research since they’ll never be finished, and thus the results of those studies will never be published.
“We learn from each other with our published data,” says Ross. “When the field is prevented from studying human tissue directly, we lack information to compare our research in other models to the human endpoint. It has a ripple effect, throughout all biomedical research, when we don’t know whether the systems we’re simulating are really relevant.”
“We have no idea what’s going to happen.”
Roxana Moslehi, a genetic epidemiologist at the State University of New York at Albany, has used placental tissue to study genetic risks of certain pregnancy complications, such as premature birth and preeclampsia, a potentially dangerous type of high blood pressure. In order to identify the biological mechanisms and specific molecular pathways involved in such conditions, Moslehi needs to look at gene expression patterns in the placentas of affected and unaffected pregnancies. The ultimate goal of her research, she says, is to find clues that could be translated into treatments or preventive measures for these conditions.
At delivery, the placenta is classified as maternal tissue, but in the case of a miscarriage or termination of pregnancy, the placenta is considered fetal tissue, and therefore subject to the new regulations. Moslehi’s lab was planning to apply for extramural NIH funding to continue this work, but since it would require using placentas from early and mid-gestation fetuses, she’s not sure if she will go forward. It’s also unclear whether one of her collaborators, an NIH scientist, will be able to continue working with Moslehi’s team under the new regulations.
Cunningham, from the Christian Center for Bioethics and Human Dignity, says there are “plenty of private funds” available for fetal tissue research, including pharmaceutical or biotech companies, private foundations, and patient advocacy organizations. But private funding sources may pose their own problems. They may not have the same ethical guidelines as NIH-funded research, and privately-funded research may be used to advocate for a given cause or agenda.
“If you keep the private funds out of this, you can maintain greater control and greater oversight over the use of such materials,” Ploss says. “With NIH grants, there are a lot of checkboxes you have to fill. In that sense, I think it’s better for this to happen under a more controlled setting.”
Aguirre and Moslehi say that if it becomes prohibitive to do such research in the United States, some scientists might decide to move their work to countries that have more lenient regulations around fetal tissue. (Some American scientists left the U.S. for similar reasons when the George W. Bush administration restricted stem cell research.) Aguirre, who is originally from Spain, says he’ll consider moving to Europe if a wider ban is implemented, as some news reports have suggested may be possible.
Many abortion opponents, like Cunningham, say they are not opposed to all research uses of fetal tissue — just when it is obtained from elective abortions. She says there are ethical sources of fetal tissue, which include tissue from miscarriages and stillbirths.
But miscarriages rarely happen in a hospital or doctor’s office, making them an unreliable source of fetal tissue. For miscarriages that happen early in pregnancy, there might not be enough or any tissue available for researchers to work with, Ploss says. And since many miscarriages result from genetic or other developmental abnormalities in the fetus, the tissue might not be suitable for research at all.
In December, NIH announced $20 million in funding for research on alternative models that do not rely on human fetal tissue from elective abortions. But while hopeful substitutes are being developed, scientists say they’re not yet advanced enough to completely replace fetal tissue. One proposed alternative is induced pluripotent stem cells, which are derived from adult blood or skin cells and mimic embryonic stem cells. They’re seen as a more ethical alternative because they don’t involve embryos or fetal tissue. But it’s difficult to make these cells, and they don’t always work. And scientists still need to compare these cells to the real ones found in fetal tissue to make sure they can use them for a side-by-side comparison.
Organoids, which are tiny, 3D organ-like structures, are also being explored as a possible substitute for fetal tissue. They have been used to study diseases and test drugs but raise new ethical questions of their own.
Ploss says he thinks the new round of funding for alternative models is a good idea, but that fetal tissue should still be available to researchers who need it.
At a time when a number of states have imposed stricter laws on abortions, fetal tissue research is likely to remain controversial. But scientists like Ploss who work with fetal tissue don’t do it because they like it — they do it because it offers them the best way possible to discover medical answers that we all need. “Until we have those alternatives, we need to leave this on the table and have it as an option.”