A federal judge on Monday temporarily blocked the Obama administration's efforts to expand cell stem research, arguing that such research destroys human embryos.
Although the George W. Bush administration had limited embryonic research to existing lines of cells, President Obama last year lifted that prohibition.
The move prompted a lawsuit from adult-stem-cell researchers, who said the expansion violated a prohibition on federal funding for research that destroys human embryos. The adult-cell researchers were concerned the expansion of the embryonic cell lines would limit their access to federal funds.
Nightlight Christian Adoptions, a nonprofit group that promotes and facilitates adoptions, also signed on to the lawsuit. The group, which offers a program allowing infertile couples to adopt frozen embryos, said the expansion of embryonic research will reduce the number of available embryos.
U.S. District Judge Royce Lamberth on Monday agreed, ruling that embryonic stem cell research "depends upon the destruction of a human embryo."
The ruling does not overturn Obama's expansion, but freezes the expanded research while the lawsuit proceeds.