Dec. 23, 2013 -- Erick and Marlise Munoz, both paramedics in Tarrant County, Texas, had talked a lot about end-of-life decisions, including the importance of do-not-resuscitate orders. So when doctors put her on life support after suffering a suspected pulmonary embolism last month, her husband says, he knew her wishes.

Marlise, 33, had lost a brother years before and told her husband she never wanted to be kept alive by machines, he says.

But Marlise is pregnant, and Texas state law puts the rights of a fetus over the wishes of its mother. The baby Marlise is carrying is now closer to 18 weeks, but Munoz says doctors have no idea what effects the oxygen deprivation Marlise has suffered will have if the baby is delivered.

"It's hard to reach the point where you wish your wife's body would stop," Munoz, also in his 30s, told ABC News' Dallas-Fort Worth affiliate WFAA-TV.

"They don't know how long the baby was without nutrients and oxygen," he said. "But I'm aware what challenges I might face ahead."

Marlise, who with her husband has a 1-year-old son, has been on life support at John Peter Smith Hospital in Fort Worth since Nov. 26, when Munoz found her collapsed on the living room floor. He performed CPR and then called 911. She never regained consciousness and her husband says she is now "simply a shell."

But the fetus still has a normal heartbeat.

Munoz told ABC News that he knows his desire to end his wife's life support is unpopular with many people

Family lawyers have said it will be difficult to convince a Texas judge to grant an injunction or restraining order to put the mother's wishes ahead of her child.

Munoz said that although he and his wife had intended to sign a do-not-resuscitate order, or DNR forms, they had not done so before she fell ill.

Texas law states this on pregnant patients: "A person may not withdraw or withhold life-sustaining treatment under this subchapter from a pregnant patient."

And on DNR forms, under the Health and Safety Code, it reads, "I understand under Texas law this directive has no effect if I have been diagnosed as pregnant."

Hospital officials would not speak directly about the Munoz case, but told ABC News: "We have families every day that face really difficult decisions when it comes to the care of their loved ones and we would have the same response. We follow the law."

Art L. Caplan, director of the medical ethics division at NYU's Langone Medical Center, said that at 18 weeks, the fetus is not viable, but could be kept alive and delivered by cesarean at 24 to 28 weeks.

"We don't know if these babies have been healthy," he said. "We tend to see that these babies are born, then it's the end of the headline. ... We don't know the impact of life support on fetal development and the wife being robbed of oxygen. ... It could be a huge challenge for the fetus."

Caplan said several other states, like Texas, have riders that void living wills when women are pregnant. But most legal cases favor the rights of the mother.

"The basic moral principle with the individual is you do not have to give them care they do not want," he said. "The principle has been established again and again throughout legal cases in the United States."

The most notable right-to-die case was that of Terry Schiavo, a brain-dead Florida woman whose family fought to keep her alive.

But her husband eventually won a court order in 2005 to withdraw her feeding tube and Schiavo died at the age of 41.

Caplan said he supported Munoz's plea to grant his wife's end-of-life wishes.

"It sounds like they are well-informed people -- he is an EMT and she is a paramedic -- around a lot of resuscitation," Caplan said. "And she was clear about her wishes, if she had an understanding at the time of these discussions when she was pregnant."

Fears that the child might also be brain-damaged could be a concern of the father, Caplan said. "It's a high risk."

"As much as we might want to save the fetus, if both parents agreed that they didn't want technology to keep [the fetus] alive and thought about it and discussed it, then to me Texas law could be overridden by a judge who says there is a right to stop life support," he said.

Although Munoz disagrees with the law, he says, he does not want to wage a long battle over the issue.

"You just never think it's going to be you," he said.