RALEIGH, N.C. — Pregnant women routinely give urine samples as part of their physical exams. A new study shows those tests may, one day, tell doctors which women are at risk of developing dangerously high blood pressure, a condition called preeclampsia.

Beth Nance never had serious health problems before, but 6-1/2 months into her pregnancy with daughter Caroline, something happened.

"I started feeling really tired, more so than usual, and I started noticing that I was having a lot of swelling," Nance said.

Nance had migraine headaches and blurred vision. A checkup revealed high blood pressure. She had preeclampsia, a condition that kills hundreds of women in the U.S each year and leads to 15 percent of premature births.

"The biggest problem is there's no cure for preeclampsia. The way to cure preeclampsia is deliver the placenta," said Dr. Dawan Gunter, of Rex Health Care.

There are some invasive tests that can help predict preeclampsia, but the condition only occurs in 8 percent of pregnancies. A new study in the

Journal of the American Medical Association

shows a simple urine test may reveal which women are at greatest risk. They have the lowest levels of a certain protein called placental growth factor.

"But from my understanding, it is a test in development and we probably won't see for awhile," Gunter said.

Even when the test is available, it will not prevent preeclampsia, but it could help doctors monitor those women more closely and quickly prescribe medications to control blood pressure and prevent seizures.

But for awhile, it was a serious threat for Beth Nance and her daughter, who was born six weeks early.

"She's perfectly healthy and is just perfect," Nance said. "I'm not on any kind of medication and feeling very fantastic."

Health officials said the condition could become a problem again with future pregnancies. They said if pregnant women notice severe swelling in their feet and hands and feel unusually tired, they should see their doctors right away.