This is an important study and perhaps much needed information regarding the difficult time that we as physicians have in determining the causes of premature birth.

This article has been recently quoted in a number of sources including:

US News and World Report , CBS News, and The Washington Post. 

Here is a synopsis from Medpage

By Judith Groch, Contributing Writer, MedPage Today
Published: August 26, 2008
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

STANFORD, Calif., Aug. 26 — Previously unrecognized culture-resistant microbes in amniotic fluid may be a significant cause of premature birth, according to a retrospective study. 

An analysis using both culture and polymerase chain reaction (PCR) of amniotic fluid from women in preterm labor found that 15% of the fluid samples harbored bacteria or fungi, a 50% increase over the 10% detected by conventional culture, Daniel B. DiGiulio, M.D., of Stanford University, and colleagues reported in the August 26 issue of PLoS ONE.

The heavier the burden of infection, the more likely the women were to deliver younger, sicker infants, the researchers said.

The clinical question that remains is whether or not TREATING amniotic fluid infections with antibiotics will improve outcomes for pregnant patients in preterm labor.   Current evidence based recommendations suggest that patient’s with imminent preterm birth should recieve antibiotics to avoid infection with Group B Strep once they are in labor and in many hospitals, patient’s continue to recieve antibiotics with threatened premature birth.  This study provides food for thought on a few fronts.

1. It is concievable that many patient’s in premature labor actually receive antibiotics which are not effective against the agent that is causative of their preterm labor.  In this situation, antibiotics are ineffectual at best and may worsen the situation by allowing growth of selective growth of resistant organisms at worst.
2. Traditional teaching is that an infection in the uterus should be treated by antibiotics and evacuation of the contents of the uterus.  We may be trying to keep fetuses in utero, which are best delivered.
3. Perhaps the solution would be to determine which organism is present (if any) and then determine the optimal treatment (ie, antibiotics, delivery, tocolysis + antibiotics, antibiotics + delivery, etc)

Clearly, more research is necessary in this important area.