"Researchers have developed a blood test that they say could help physicians predict whether pregnant women will deliver their babies prematurely.  The test isnt ready for prime time however and its not foolproof a study found that it misses some premature births and incorrectly predicts others. Still the test should be an important tool for an obstetrician who currently has no clue if premature birth is a possibility until it happens said Brigham Young University BYU chemistry professor Steven W. Graves. Physicians will be able to use a simple blood test and then know that this woman is at increased risk or reduced risk of a preterm birth said Graves whose laboratory performed the research in the study. About  percent of births are premature and the rate rises to  percent among women who have already had a baby prematurely Graves said. Premature birth can lead to a long list of medical problems and puts babies at risk of dying. In the new study the researchers examined blood samples from  women who went on to have normal births and  who had premature births. They tried to find signs in the blood that indicate what kind of birth the women would have.  The researchers developed a screening method that looked for socalled peptide biomarkers in the blood that  in tandem with several other proteins  predicted  percent to  percent of the premature births at  weeks of gestation. The false positive rate  referring to tests that wrongly indicated premature birth  was  percent. The test wasnt as effective at  weeks of gestation. This may simply indicate that some of the causes for preterm birth may not preexist before the pregnancy Graves said. Most probably dont but develop or become apparent as the pregnancy progresses. The closer to the preterm birth the more likely you are to have significant changes in the physiology of the woman that is observed in the blood. The test may cost  to  Graves said. It would require several years to go through the U.S. Food and Drug Administration approval process. BYU and the University of Utah have a patent on the test and have licensed it. Even if the test is found to indicate that a birth will be premature physicians would have limited options. One option is to provide drugs that dampen the immune system so the babys lungs develop faster said Dr. Jennifer Wu an obstetriciangynecologist at Lenox Hill Hospital in New York City.  Wu said the study results are promising but more research is needed to confirm that the test is reliable. If you are going to be alarming a patient by saying that she may have premature delivery you want to make sure thats truly the case. The study appears in the May issue of the American Journal of Obstetrics  Gynecology. More information For more about premature birth http visit the U.S. National Library of Medicine. SOURCES Steven W. Graves Ph.D. professor of chemistry and biochemistry Brigham Young University Provo Utah Jennifer Wu M.D. obstetriciangynecologist Lenox Hill Hospital New York City May  American Journal of Obstetrics  Gynecology"