Infections could be the cause of a number of premature births, say researchers. A study by a team at Stanford University in California found that about one out of seven women who had bacteria or fungi in their amniotic fluid went into pre-term labor. The heavier the infection, the more likely were the women to deliver babies earlier or babies who were sicker.

Dr. Dan DiGiulio, who worked on the study, said, "If we could prevent these infections in the first place, or detect them sooner, we might one day be able to prevent some of these premature births."

Reported in PLoS One, the online journal of the Public Library of Science, the study used specialized molecular testing in order to try to uncover microbes and germs that regular methods may miss. It showed more women who had infections than was previously estimated.

Dr. David Relman, the study's senior author and Stanford University microbiologist said, "We don't think any organisms belong in the amniotic sac. You'd have to presume there's something wrong."

A baby is called pre-mature if it is born before the completion of 37 weeks of pregnancy. Every year in the United States more than half a million babies are born prematurely and these are numbers that have steadily risen over the last two decades. As doctors don’t know the exact cause of these pre-term births they are often unable to prevent them.

Premature babies face a number of health risks from breathing problems, underdeveloped organs, infections to cerebral palsy. The younger the baby is when it’s born prematurely the greater the health risks it faces and babies who are born before 32weeks face the greatest risk of death and severe disabilities.

Doctors have always known that certain infections such as vaginal or urinary tract infections raise the risk of premature labor by causing inflammation that could set off labor. Dr .Michael Katz of the March of Dimes, who wasn't part of the new study, questioned how much of a role infections could play especially when they do not manifest any outwardly symptoms.

The research team from Stanford tried a new approach where they studied samples of amniotic fluid collected from women who had gone into premature labor between 1998 and 2002. Earlier the samples were tested with the standard methods and now Relman and research fellow Dr. Dan DiGiulio used a new method of testing called PCR to try to find and reproduce bits of genetic material from germs.

The PCR test detected 56 % more infected women than the standard testing had. 17 bacterial species of germs were found including one type that had not been seen previously, and one fungus. Standard tests were said to be particularly likely to miss infections in cases where the babies were born extremely prematurely at 25 weeks.

"It's a very, very important first step. But, "there are still many hurdles," said the March of Dimes' Katz regarding the research. Currently Relman's team, with funding from the National Institutes of Health, is studying 2,000 women who get routine amniocentesis in their second trimester, to try to find an answer to if germs can really predict who goes into premature labor and then to find a treatment to help.