FRIDAY, Feb. 28, 2003 (HealthDayNews) -- British researchers have cast yet another vote in the ongoing debate over whether treating certain vaginal infections during pregnancy can prevent pre-term birth.
Their study found that when treatment was rendered during the first 20 weeks of pregnancy, the rate of premature birth was cut by a dramatic 60 percent.
The study, by researchers from the Imperial College of Medicine in London, appears in the March issue of Obstetrics and Gynecology.
As impressive as those findings sound, they join the ranks of numerous other studies arriving at clearly conflicting conclusions.
"Some researchers have found that treatment reduces premature birth, others have found it does not help, and at least one study has found that treatment during pregnancy actually increased the risk of premature birth. So in my mind, this study is another piece of the puzzle, but it certainly does not offer any definitive answers," says Dr. Andrei Rebarber, director of Maternal Fetal Medicine at New York University Medical Center, who was not involved in the research.
According to the British researchers, the point of the new study was not so much to test the theory of treatment versus non-treatment, but to hone in on more specific aspects of how and when the treatment is administered.
"This study was conducted to assess whether the use of intravaginal antibiotic used early in gestation would reduce the incidence of pre-term birth," the researchers write in the journal. They also point out that in previous studies, oral antibiotics were primarily used and the timing of treatment may have been more varied.
While doctors aren't sure why certain vaginal infections can lead to pre-term birth, Rebarber says several theories exist.
"It could be that an infection encourages cervical ripening," Rebarber says. In this instance, the cervix dilates sooner than it should, setting the labor process in motion. In addition, the infecting organism may also irritate the uterus, causing contractions to begin.
"The combination of the contractions and the cervical ripening work together to encourage a pre-term birth," Rebarber says.
"What we don't know," adds Rebarber," is why some women are susceptible while others are not."
In the new study, the researchers gathered 409 pregnant women each diagnosed with abnormal genital tract flora -- indicative of one of several simple vaginal infections -- somewhere between their 13th and 20th week of pregnancy.
The women were randomly selected to receive either a three-day treatment with Clindamycin vaginal cream, or a placebo cream.
The final outcome of the study was determined after all the women had given birth: Just 4 percent of those treated with the Clindamycin cream experienced a pre-term birth, compared to 10 percent in the placebo group.
Of the babies born pre-term, 63 percent required admission to the neonatal intensive care unit, compared to just 4 percent of the full-term infants.
"A 2 percent Clindamycin vaginal cream ... administered to women with abnormal genital tract flora before 20 weeks gestation can reduce the incidence of pre-term birth by 60 percent, hence the need for neonatal intensive care," the researchers say.
While Rebarber isn't convinced that all pregnant women with vaginal infections need treatment, he says those at high risk for premature birth could benefit.
The other deciding factor can be the type of infecting organism that is diagnosed. When that organism is Strep B, for example, treatment may become necessary, he says.
More information
For more information on complications of premature birth, visit The March of Dimes. To learn more about vaginal infections, check out The National Institute of Allergy and Infectious Diseases.
