A simple urine test during pregnancy could someday predict which women are likely to develop dangerously high blood pressure called pre-eclampsia, a condition that kills hundreds of mothers-to-be each year in the United States and leads to 15 percent of all premature births, researchers say.
Pre-eclampsia occurs in as many as 8 percent of U.S. pregnancies, often striking healthy women without warning, and can lead to seizures, strokes and kidney damage. The cause is unknown, and there is no reliable way in use today to predict who will develop it. The only known cure is to deliver the baby, often prematurely.
But a new study offers hope for the development of a urine test over the next few years that could identify high-risk women several weeks or even months before pre-eclampsia develops.
The study found that urine samples from women who eventually developed pre-eclampsia had extremely low levels of a protein called placental growth factor, which nurtures blood vessels that support the mother and fetus.
The same researchers reported last year that blood samples also can predict the disease. But they said a urine test could allow women to screen themselves and would be much easier to administer in Third World countries.
While a screening test would not prevent the disorder, doctors could monitor at-risk women more closely to prevent complications, and such patients could, for example, be put on blood pressure drugs or medication to prevent seizures.
The study, published in Wednesday’s Journal of the American Medical Association, compared samples from 120 women who eventually developed pre-eclampsia to specimens from 118 women who did not develop the condition.
Women with the lowest placental growth factor levels were nearly 23 times more likely to develop pre-eclampsia before their 37th week of pregnancy than the rest of the women. Researchers detected low levels of the protein as early as the 25th week of pregnancy.
“If there were a self-administered test developed, similar to a pregnancy kit, it could tell women if they’re in trouble and to see their doctor right away,” said Dr. Richard Levine, the study’s lead author and research medical officer at the National Institute of Child Health and Human Development, which funded the research.
Levine estimated it would take at least four years to develop such a test.
Dr. Cathy Spong, chief of the pregnancy and perinatology branch of the National Institute of Child Health and Human Development, said researchers have searched for decades for a predictor of pre-eclampsia.
“These findings are very exciting,” Spong said. “But just because we know they’re going to develop pre-eclampsia, if it develops early on, it could still have devastating outcomes. Ideally we’d like to get to intervention.”
Levine said placental growth factor could someday be given to at-risk women to prevent pre-eclampsia.