Influence of bacterial vaginosis on conception and miscarriage in the first trimester: cohort study. Issue 7204 (24th July 1999)

• Record Type: Journal Article
• Authors: Ralph, S G; Rutherford, A J; Wilson, J D
• Is Part Of: BMJ. Volume 319:Issue 7204(1999)
• Page Start: 220
• Page End: 223
• Publication Date: 1999-07-24
• Subjects: Medicine -- Periodicals; Medicine -- Periodicals; Medicine; Periodicals; 610
• DOI: 10.1136/bmj.319.7204.220
• Languages: English
• ISSNs: 0007-1447

Abstract

Abstract: Objectives: To assess whether bacterial vaginosis affects the rates of conception and miscarriage in the first trimester. Design: Cohort study. Setting: Assisted conception unit of a teaching hospital in Leeds. Participants: 867 consecutive women undergoing in vitro fertilisation. Interventions: Screening for bacterial vaginosis with a Gram stained vaginal smear before egg collection. Main outcome measures: The presence of bacterial vaginosis or normal vaginal flora, and the rate of conception and miscarriage in the first trimester. Results: 190 of 771 (24.6%) women had bacterial vaginosis. No difference in conception rate was found between those women with bacterial vaginosis and those with normal vaginal flora: 61 women (32.1%) and 146 of 493 women (29.6%) respectively (relative risk 1.08, 95% confidence interval 0.85 to 1.39; odds ratio 1.12, 0.77 to 1.64). However, 22 women (31.6%) with bacterial vaginosis who conceived had a significantly increased risk of miscarriage in the first trimester compared with 27 women (18.5%) with normal vaginal flora (crude relative risk 1.95, 1.11 to 3.42; crude odds ratio 2.49, 1.21 to 5.12). This increased risk remained significant after adjustment for factors known to increase the rate of miscarriage: increasing maternal age, smoking, history of three or more miscarriages, no previous live birth, and polycystic ovaries (adjusted relative risk 2.03, 1.09 to 3.78; adjusted odds ratio 2.67, 1.26 to 5.63). Conclusions: Bacterial vaginosis does not affect conception but is associated with an increased risk of miscarriage in the first trimester in women undergoing in vitro fertilisation, independent of other risk factors.