Effect of oral N-acetyl cysteine on recurrent preterm labor following treatment for bacterial vaginosis

Objective: To evaluate the effect of N-acetyl cysteine (NAC) on gestational age at delivery in women previous preterm labor and bacterial vaginosis. Methods: A randomized, double-blind, placebo-controlled trial with 280 women between 16 and 18 weeks of pregnancy who had 1 previous preterm birth and had just been successfully treated for bacterial vaginosis with metronidazole for 1 week. The women were randomized to receive 0.6 g of NAC per day plus 17-hydroxyprogesterone caproate (17-OHPC) or placebo plus 17-OHPC until 36 completed weeks of pregnancy or active labor. A vaginal swab was taken during labor. Results: Reaching 36 weeks of pregnancy was more frequent (P<0.05) and gestational age at delivery was significantly higher in the NAC than in the placebo group (37.4 weeks +/- 0.4 weeks vs 34.1 weeks +/- 1.2weeks, P<0.05). The discontinuation rate was 11.4% in the NAC group. Conclusions: Oral NAC was found to reduce the recurrence of preterm birth in patients with bacterial vaginosis. (C) 2008 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights