CONWAY, South Carolina (AP) -- A woman was convicted Wednesday and sentenced to 12 years in prison for killing her unborn child by using crack cocaine during her pregnancy.

The verdict marks the first time a woman in the United States has been found guilty of homicide for taking drugs during pregnancy, an advocate for the defendant claimed.

The case also opens the door for prosecutors to charge women with neglect under other conditions, such as smoking during pregnancy, said Wyndi Anderson, executive director of the South Carolina Advocates for Pregnant Women.

A jury found Regina McKnight, 24, guilty after deliberating just 15 minutes. She could have faced a life sentence. McKnight's lawyers said they will appeal.

The state Supreme Court ruled in 1996 that a viable fetus is they took drugs after their unborn child was able to live outside the womb.

McKnight's baby was stillborn in 1999 at 35 weeks. She is the mother of three other children and is two months pregnant.

"The state needed to press forward because a child ended up dead," prosecutor Bert von Herrmann said. "She smoked cocaine as much and as often as she could ... if that's not extreme indifference to life, I don't know what is."

But defense attorney Orrie West said the brief deliberations indicate the jury punished McKnight because she was a drug addict.

"Given almost all of the trial involved complex medical testimony, I don't think the jury weighed it like they should," West said.

The defense said an inflammation of the placenta, which could have at least two causes other than drug use, killed the fetus.

This was McKnight's second trial; a mistrial was declared in January after two jurors used the Internet to look up medical information.