New York, Jan 24 (IANS): The presence of bacteria in a woman's vagina and cervix may either increase the risk of premature birth or have a protective effect against it, researchers say.

Premature birth -- baby born before 37 weeks of pregnancy -- is the leading cause of death in children under the age of five around the world. 

Contrary to conventional studies which say that premature birth begins in the uterus, the new research showed that the presence of some bacteria conferred a lower risk of spontaneous preterm birth while other bacteria were associated with a significant increased risk. 

"The study found significant differences in the microbial communities early in pregnancy in women who ultimately have a preterm birth compared to a term birth," said Michal Elovitz from the University of Pennsylvania. 

"Different bacterial species were associated with quite a dramatic increased risk of premature birth. If our study is confirmed, it could mean that targeting CV bacteria may be a new therapy to prevent premature birth in the immediate future, not decades from now," Elovitz added.

For the study, the team examined 2,000 pregnant women, taking vaginal swabs at three distinct time points in pregnancy and performed analyses on the specimens to determine the microbial colonies that were present. 

They hypothesised that there is some difference in the molecular, biological, biochemical and/or microbial events in cervicovaginal space in women who ultimately have a premature birth compared to women who ultimately have a full term baby. 

The study may help to prevent preterm birth either by eliminating the cervicovaginal bacteria that are associated with an increased risk and/or by enhancing the presence of protective bacteria. 

The findings will be presented at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting in Las Vegas.