DALLAS — Bishops hashed out the thorniest issues in cutting-edge medicine in Dallas this winter.

More than 150 bishops from the United States, Canada, Mexico and the Philippines gathered at the biannual bishops’ workshop of the National Catholic Bioethics Center, held here Feb. 5-7.

Dr. John Haas, president of the Philadelphia-based center, raised the issue of whether a new bioethics document might be forthcoming — 20 years after the Congregation for the Doctrine of the Faith published Donum Vitae (Gift of Life), the instruction that taught that both artificial insemination and in vitro fertilization were contrary to the moral law.

Cardinal William Levada, prefect of the Congregation for the Doctrine of the Faith, was participating in the workshop. While stopping short of promising a new document, he did spell out new bioethics questions.

“The particular issues addressed in Donum Vitae may seem to us today rather limited in scope in comparison with the technological developments of the past 20 years,” Cardinal Levada said in his closing address. “Today, of course, we face a new set of bioethical challenges: cloning, gene therapy, stem cell production and research, pre-implantation diagnosis, banks of sperm cells and eggs for commercial use, etc. … But our response to the many new challenges, and to the old ones as well, must involve helping our people understand these technologies in the light of the underlying principles that correspond to the plan and design of God himself.”

The workshop — the 21st one held since 1980 — tackled the thorniest issues, including those on which Catholic moral theologians are divided and the magisterium has not yet pronounced.

One such debate was held on the morality of adopting “leftover” frozen embryos from in vitro fertilization clinics.

Dr. Edward Furton, the National Catholic Bioethics Center’s director of publications, argued in favor of such adoptions, likening them to adoptions of already-born children, but with the added dimension that the adoptive mother would have carried the child in utero.

Father Nicanor Austriaco, a biologist at Providence College, argued the opposite, saying that gestating a child that was not conceived as the fruit of a marital act separates the unitive and procreative dimensions of conjugal relations, and is therefore morally illicit.

While the latter position is a distinct minority among Catholic moralists, it is held by prominent experts, including Father Tadeusz Pacholczyk, the National Catholic Bioethics Center’s director of education and a well-known lecturer on bioethics.

Father Pacholczyk updated the bishops on the science of stem cells, pointing out that since the last bioethics workshop in 2005, there has been promising research on gathering stem cells in a morally legitimate way — liposuction, placenta and amniotic fluid.

Nevertheless, despite the fact that embryonic stem cells have produced to date no successful human therapies, Father Pacholczyk expected that the push for more public funding will continue.

“The irony is that the push for public funding of embryonic stem-cell research — which kills the embryo — is driven by the fact that private research funding stays away from embryonic stem-cell research precisely because it is not promising from a purely scientific point of view,” he said.

The bioethics’ workshop was also addressed by Carl Anderson, Supreme Knight of the Knights of Columbus, which has underwritten the conference for nearly two decades.

Other topics covered in the workshop:

• feeding tubes for comatose patients,

• brain death and organ donation,

• emergency contraception for rape victims,

• vaccines derived from aborted children, 

• contraceptive coverage mandates.

Register correspondent Father Raymond J. de Souza also addressed the workshop on the media dimension of bioethical matters.