Amniotic Fungi May Up Preterm Births

Aug. 25, 2008 -- Using new technology, Stanford researchers find that bacteria and fungi in amniotic fluid may contribute to many premature births.

An analysis of amniotic fluid from women in preterm labor shows that 15% of the fluid samples harbored bacteria or fungi -- an increase of 50% over estimates using traditional testing.

"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," says research associate Dan DiGiulio, MD, in a news release. DiGiulio conducted the study in the laboratory of the study's senior author, David Relman, MD, professor of infectious disease, microbiology and immunology at Stanford University School of Medicine.

Researchers used a highly sensitive technique called polymerase chain reaction (PCR) to track down micro-organisms in amniotic fluid samples collected from women in preterm labor.

Previous efforts to conduct a census of bacteria, fungi, and other microorganisms in the fluid relied primarily on culturing the organisms in a lab after withdrawing some of the liquid through a needle inserted into the amniotic cavity. But not every microbe survives the process, so it has been hard to measure the true number of microbes.

In the Stanford study, published in PLoS ONE, researchers used both PCR and lab cultures. They looked at fluid samples from 166 women in preterm labor; 113 of the women went on to deliver premature babies.

The women were patients at Hutzel Women's Hospital in Detroit between October 1998 and December 2002. Twenty-five of the 166 samples were infected with either bacteria or fungi. Seventeen different bacterial and one fungal species were identified in the positive samples with the combined PCR and culture analysis -- far more than the 11 found by conventional analysis. The investigation also turned up a novel microorganism that may represent a previously unknown species.

The researchers write that the findings do not prove that underlying infection of the amniotic cavity is cause for premature birth. They call for more research to investigate further.