As 1-year-old conjoined twins from Egypt gurgle in their crib, authorities are faced with a puzzling dilemma: Should one baby be sacrificed at the expense of the other? 

Coming up with an answer has produced debate among doctors, ethicists and religious leaders from America to the Middle East. Factors being evaluated include their quality of life and the possibility of surgical success in separating the twins, who are connected at the crowns of their heads. 

"To perform the surgery is to make the judgment that the quality of life attached is so poor that it's not worth living to preserve it," said Richard Burgh, who teaches medical ethics at Rider University in Lawrenceville, N.J. "That's also an ethical judgment which as a society we are loath to make." 

Doctors determined earlier this month that separating Mohamed and Ahmed Ibrahim might be successful, but could result in the deaths of one or both. The twins could live indefinitely if nothing is done. 

The twins were born June 2, 2001, to the wife of a laborer in a remote Egyptian village. The babies and their Egyptian doctors flew to Texas last month to be evaluated by craniofacial surgeon Dr. Kenneth Salyer and a team of specialists at North Texas Hospital for Children. 

Salyer said that while a good portion of each brain is separate, the attachment in their heads is extensive and includes the connection of blood vessels. 

Dr. Nasser Abdel Al, head of neonatal surgery at the Abu el-Reesh Hospital in Cairo, returned to Egypt to consult with religious and medical experts about the possible scenarios: a successful separation, a separation in which one dies, the death of both, complications causing brain damage in one or both, or skipping the surgery. 

Doctors and nurses at the Cairo hospital, where the twins had been cared for since shortly after their birth, pleaded for separation this weekend, Abdel Al said. 

He is informally surveying Egyptian citizens about the twins' plight, which has captured wide attention in conservative, predominantly Muslim Egypt. He also planned to discuss the twins' future with their parents. 

Abdel Al said decisions on their treatment have to be carefully and publicly formulated "so everyone will feel at ease. If any complications do arise, then they know we are doing everything we can." 

The playful twins have spent the first year of their lives on their backs, often reaching back to grab the other's ear or nose. They also appear eager to move, trying to push each other up. 

In late 2000, surgeons in Great Britain separated twin girls joined at the abdomen, knowing they would hasten the death of the weaker twin even as they saved the life of her stronger sister. 

The parents told doctors and the courts they wanted to leave matters in the hands of God, even if it meant both girls' deaths. 

The judges ultimately decided that the weaker twin was living on borrowed time and chose surgery — and a chance at a normal life — for the stronger one. The weaker infant died. 

Conjoined twins are highly rare. They form when a fertilized egg fails to fully separate, unlike identical twins that develop when the egg splits into two embryos early during pregnancy. 

The World Craniofacial Foundation, a nonprofit foundation based in Dallas, is paying for the Egyptian twins' trip and organizing the doctors volunteering to work with them. 

Foundation director Sue Blackwood said doctors are doing more testing in preparation for the possible surgery. She said there are no percentages on the chance for survival. 

Marvin Newman, professor of legal studies and communication at Rollins College in Winter Park, Fla., said it's important to get several medical opinions. 

"It's really a weighing process," said Newman, who serves on the ethics committees of several hospitals around the world. If they remain connected, "they'd be terribly debilitated and they'd have a terrible quality of life," Newman said. 

Ibrahim Hooper, a spokesman for the Council on American-Islamic Relations, a Washington-based Islamic advocacy group, said seeking religious consultation is important in Islamic society. 

"I'm sure it would be taken into account by the family," Hooper said. "It would be like your doctor telling you something about medicine. If a well-respected scholar tells you something about your faith you're likely to take it into consideration."