Primary prevention with vaginal chlorhexidine prior to 16 weeks reduces the incidence of preterm birth. Results of the PLUVA (Preterm Labor prevention Using Vaginal Antiseptics) study.

: Preterm labor (PTB) is one of the leading causes of perinatal death and is currently considered a syndrome with many causes. One of the most important is ascending infection, derived from bacterial vaginosis (BV). Chlorhexidine (CLX) has proven to be effective against BV and against bacterial biofilms without affecting gestation. : We aimed to evaluate the effectiveness of a universal primary prevention strategy for PTB using intravaginal CLX applied before 16 weeks (preterm labor prevention using vaginal antiseptics, PLUVA study). : We performed a prospective observational study with two cohorts of pregnant women that were assigned either to prevention of PTB by means of intravaginal CLX (Cum Laude CLX®, CLX digluconate 0,2%) before 16 weeks (N=413), or to no treatment following the usual hospital protocol (N=704). Primary outcomes were the incidence of spontaneous PTB below 34 and 37 weeks, the incidence of PTB below 34 and 37 weeks including inductions for premature rupture of membranes (PRM), and the incidence of PTB below 34 and 37 weeks including any indication for termination of pregnancy. Both cohorts were compared by means of Mann-Whitney and Fisher tests. Finally, a multivariable analysis including the odds ratio (OR) was performed, adjusting for clinical parameters, to evaluate the importance of the different determinants in the prediction of PTB. : In pregnancies treated with chlorhexidine the incidence of spontaneous PTB, PTB including induction for PRM, and PTB including any indication for termination of pregnancy was respectively at 34 and 37 weeks: 0%, 0%, 0.24% and 1.69, 2.90% and 3.15%, while in non-treated pregnancies this incidence was 9%, 11%, 12% and 23%, 35% and 43%. According to the multivariable analysis, women treated with CLX prior to 16 weeks halved the incidence of PTB (OR 0.52, p<0.05). : Universal treatment with vaginal CLX before 16 weeks reduces the incidence of PTB, especially before 34 weeks.