Changes in the vaginal flora after two percent clindamycin vaginal cream in women at high risk of spontaneous preterm birth

Objective To analyse alterations in the vaginal flora after 2% clindamycin vaginal cream or placebo administered for the prevention of preterm delivery in high risk women. Design Observational study during a randomised multicentre double-blind placebo controlled trial. Setting Twelve city hospitals in The Netherlands. Participants One hundred and sixty-eight women were enrolled. Alterations in the vaginal flora could be analysed in one hundred and twenty-four women by comparing the Nugent score on entry to the trial and at 31 weeks' gestation. The Nugent score was classified into normal, intermediate and bacterial vaginosis. Interventions Two percent clindamycin vaginal cream or placebo cream administered daily for seven days at week 26 of pregnancy. Main outcome Changes in the vaginal flora at week 31 of pregnancy. Results The placebo group consisted of 64 women and the clindamycin group of 60 women. At week 31 the vaginal flora was similar to week 26 with placebo cream but changed from normal vaginal flora to intermediate or bacterial vaginosis with 2% clindamycin vaginal cream. Conclusion Obstetricians should not prescribe 2% clindamycin vaginal cream to pregnant women with normal vaginal flora in order to reduce the incidence of preterm birth. because it has no beneficial effects and is actually harmful. 2% Clindamycin vaginal cream encourages the presence of bacterial vaginosis which is epidemiologically associated with preterm birth.