Washington D.C., Mar 25, 2021 / 11:10 am (CNA).- After scientists successfully grew mouse embryos in an artificial uterus, ethicists are warning against any future extension of the experiments to human embryos.

Scientists working at an Israeli research institution recently sustained mouse embryos in an artificial uterus for 12 days. The experiment’s lead researcher suggested that human embryos should eventually be studied in an artificial womb, as late as 40 days post-fertilization.

“I think the greatest concern is that it [the research] doesn’t stop with mice,” said Dr. David Prentice, adjunct professor of molecular genetics at the John Paul II Institute in Washington, D.C., in an interview with EWTN Pro-Life Weekly that will air on Thursday. Prentice is also vice president of the Charlotte Lozier Institute, a pro-life research group.

On March 17, scientists reported that they had taken fertilized eggs of mice and grew mouse embryos in an artificial uterus for 11 to 12 days – longer than had ever been recorded.

Dr. Jacob Hanna, working at the Weizmann Institute of Science in Israel, led the research team for the embryo experiments. He wrote that his experiments could help fellow scientists study the development of mammals – and possibly understand more clearly how miscarriages and gene mutations can occur, the New York Times reported on March 17.

Hanna also hoped the research could extend to human embryos in the future.

He said that “I hope that it will allow scientists to grow human embryos until week five,” as reported in the MIT Technology Review. Hanna added that he is pushing for research labs to study human embryos, growing them in an artificial womb for 40 days before disposing of them.

“I do understand the difficulties. I understand. You are entering the domain of abortions,” Hanna said, the MIT Technology Review reported. “So I would advocate growing it [the human embryo] until day 40 and then disposing of it.”

The hypothetical practice could replace the fetal tissue research market, he said.

“Instead of getting tissue from abortions, let’s take a blastocyst and grow it,” he said.

In response, a Catholic ethicist told EWTN Pro-Life Weekly that the Church opposes experimentation on human embryos except for direct, therapeutic, non-harmful treatments for the embryos themselves.

“The Church has already spoken to this issue,” said Dr. Joseph Meaney, president of the National Catholic Bioethics Center, on EWTN Pro-Life Weekly. He cited the Vatican’s 1987 document Donum Vitae, “Instruction on respect for human life.”

In the document, the Vatican’s Congregation for the Doctrine of the Faith (CDF) taught that only direct therapeutic experiments are licit on human embryos, he said, adding that “nothing that would put their lives in danger could be acceptable.”

The experimentation cannot be conducted even if its motives are laudable, he said. “It’s a very good idea to look into the causes of miscarriage,” he said, adding that such research should be conducted through ethical experiments on animals and not on human embryos.

The sustaining of human embryos outside the womb for research is not licit, he explained, especially when they are discarded after a period of time.

“Procreation is all about respecting the dignity of the human person. And creating an artificial womb where the child is completely disassociated from the mother for nine months, or even just a few weeks,” he said, “all of that is completely contrary to the dignity of the human person.”

“And so these kind of experiments where they will actually be killing human beings are never something that can be done,” he said.

The Church sets ethical restrictions on research out of respect for the human person and not out of animosity toward science, he said.

“The Church is very pro-science,” he emphasized. “We always put the human person at the center of science, not to be experimented upon, but to be actually helped.”

In Donum Vitae, the Vatican CDF stated “[t]he human being must be respected – as a person – from the very first instant of his existence.”

“Medical research must refrain from operations on live embryos, unless there is a moral certainty of not causing harm to the life or integrity of the unborn child and the mother, and on condition that the parents have given their free and informed consent to the procedure,” the document said of direct therapeutic treatment.

“If the embryos are living, whether viable or not, they must be respected just like any other human person; experimentation on embryos which is not directly therapeutic is illicit,” the Vatican said.

“No objective, even though noble in itself, such as a foreseeable advantage to science, to other human beings or to society, can in any way justify experimentation on living human embryos or foetuses, whether viable or not, either inside or outside the mother’s womb.”