Treating Abnormal Vaginal Flora Decreases Preterm Birth Risk

Clindamycin administered in pregnant women with objective evidence of abnormal vaginal flora before 22 weeks of gestation significantly reduces the rate of late miscarriage and preterm birth, according to a new study.

Researchers at Wayne State University (Detroit, MI, USA) and Hutzel Hospital (Detroit, MI, USA) conducted a systematic review and meta-analysis of randomized controlled trials of early administration of clindamycin to women with abnormal vaginal flora earlier than 22 weeks, to determine whether administration reduces the risk of preterm birth and late miscarriage. Five trials comprising 2,346 women were included in the study; 3.7% of women with abnormal vaginal flora who received clindamycin delivered before 37 weeks of gestation were compared to 6.2% in the control group.

The researchers found there were no overall differences in the risk of preterm birth earlier than week 33, low birth weight, very low birth weight, admission to neonatal intensive care unit, stillbirth, peripartum infection, and adverse effects. According to the results, the researchers calculated that 40 women would need to be treated before 22 weeks of gestation with clindamycin to prevent one case of spontaneous preterm birth. The evidence was strongest for oral clindamycin, rather than clindamycin vaginal cream. The study was published early online on April 4, 2011, in the American Journal of Obstetrics and Gynecology.

"None of these systematic reviews or meta-analyses has simultaneously addressed the optimal choice of agent, the selection of patients who are infected, and the timing of intervention,” said lead author Roberto Romero, MD, and colleagues of the perinatology research branch. "There is however, equipoise to justify a randomized controlled trial of clindamycin for the prevention of preterm birth.”

Preterm birth refers to the birth of a baby of less than 37 weeks gestational age, before the developing organs are mature enough to allow normal postnatal survival. The cause for preterm birth is in many situations elusive and unknown; many factors appear to be associated with the development of preterm birth, making the reduction of preterm birth a challenging proposition. Premature infants are at greater risk for short and long-term complications, including disabilities and impediments in growth and mental development. Preterm birth is the major cause of neonatal mortality in developed countries.

Related Links:
Wayne State University
Hutzel Hospital