VATICAN CITY (CNS) -- The Vatican plans to issue a new document on bioethics that addresses human cloning, stem-cell research and other issues, informed sources said.

The Vatican instruction, prepared by the Congregation for the Doctrine of the Faith, was scheduled to be published Dec. 12, the sources said. A Vatican press conference is planned for its release.

The document was designed to examine ethical issues in biological research and health care that have emerged in recent years. When members of the doctrinal congregation met in a plenary session last January, U.S. Cardinal William J. Levada, the congregation prefect, said much of their discussion focused on the field of bioethics.

At that time, the cardinal hinted that a document was in the works. He said it might examine new therapeutic options and some ethical problems that were not explicitly considered by two previous church documents: the doctrinal congregation's instruction "Donum Vitae" ("The Gift of Life") in 1987 and Pope John Paul II's encyclical "Evangelium Vitae" ("The Gospel of Life") in 1995.

Pope Benedict XVI was head of the doctrinal congregation when both those documents were published. Addressing the congregation in January, the pope said the new ethical problems included the freezing of human embryos, the selective reduction of embryos, pre-implant diagnosis, research on embryonic stem cells and attempts at human cloning.

The pope said the starting point for the church's reflection remains the same: "The two fundamental criteria for moral discernment in this field are unconditional respect for the human being as a person from the moment of conception to natural death, (and) respect for the originality of the transmission of human life through the acts proper to spouses."

© 2008 Catholic News Service/U.S. Conference of Catholic Bishops