Background: Preterm delivery is one of the most common causes of perinatal mortality around the world. The purpose of this study was to determine the effect of clindamycin vaginal cream in the prevention of preterm labor.

Materials and Methods: This study was a control trial carried out on 236 pregnant women, referred to private practice office of a physician,with 13-20 weeks of gestational age. Samples of vaginal smear were gathered, and in the case of abnormal results, subjects were randomly assigned to either a control or case group. Clindamycin group treated with vaginal cream for three nights in the first turn and seven night at the second turn. But the control group received no treatment. Then, all subjects were followed up. Data wero collected using a questionnair and analyzed.

Results:The incidence of premature birth in the control group was higher than the group under treatment with clindamycin (12% vs 7%), but this difference was not enough to be statistically significant. It was also shown that the higher incidence of preterm delivery in the control group was lower than the age of pregnancy termination. Mortality in the control group was significantly higher than the control group.

Conclusion: Although no significant difference was observed in the rate of preterm labor between the two groups, but in control group gestational age was less and mortality rate was high. It seems that clindamycin in decreasing prenatal mortality is associated with preterm labor effectively.