Study of association of bacterial vaginosis in preterm labor and fetal outcome

Background: Preterm labor has increasing evidence of infectious cause especially ascending infections from lower genital tract, of late attention is being given to bacterial vaginosis. In many of the case control and prospective studies bacterial vaginosis has been associated with late miscarriage, preterm labor, premature rupture of membranes, chorioamnionitis. Treating bacterial vaginosis can reduce the preventable cause of preterm birth. Aim: The association of bacterial vaginosis in preterm and its fetal outcome. Material and methods: A case control study of 120 pregnant women (Study group-60 and controls 60 cases). Pregnant women with preterm labor, 28 weeks to 37 weeks were selected. Vaginal discharge pH was measured. Sterile cotton swabs were used for vaginal smear preparation for gram staining and the organisms were scored based on Nugents scoring system. Clue cells were also noted on the smear. Diagnosis of bacterial vaginosis is done in women with pH above 4.5 and a score of 7 or more on gram staining of vaginal smear based on Nugents criteria. Outcome of delivery was observed. Results: 61.6% were < 34 weeks of gestation. High vaginal pH >4.5 is seen in 55%. Chi Square test and the P value 0.001 (99.9%) showed significance of the test. Gram staining revealed bacterial vaginosis infection 41.6% in study group and 16.6% in control group. This study was in concurrence with the study made by Saifon Chawanpaiboon which showed an association between high vaginal pH, Amsels criteria and various stages of preterm labor. Neonatal complications were seen in women with preterm <34 weeks and positive for bacterial vaginosis. Conclusion: Association between bacterial vaginosis and preterm labor was established. Screening and treatment will reduce the incidence of preterm delivery.