Objectives: To estimate the prevalence of bacterial vaginosis (BV) in infertile women and evaluate the
effect of treatment of BV on the pregnancy rate in patients with polycystic ovarian disease (PCOD) and
unexplained infertility.
Study design: Cohort study conducted at the Department of Obstetrics and Gynecology in collaboration
with the Microbiology Department of Sohag University Hospital, Egypt. All eligible women with female
factor infertility (n = 874) were enrolled and all asymptomatic fertile women (n = 382) attending the
family planning clinic of the study hospital were recruited as a control group. The study was in two
phases: the first included screening all participants for BV after Gram-staining of the vaginal discharge.
The second phase was concerned with evaluating the effect of treatment of BV on the cumulative
pregnancy rate (CPP) in patients with PCOD (group I; n = 278) and unexplained infertility (group II;
n = 170). Each group was divided into three sub-groups: groups Ia (n = 129) and IIa (n = 73) were BV
positive and treated for BV; groups Ib (n = 61) and IIb (n = 49) were BV positive and did not receive
treatment for BV, and groups Ic (n = 88) and IIc (n = 48) were BV negative. The prevalence of BV was
compared using the Chi-square. The long rank test of Kaplan-Meier life table analysis was used to
compare the CPR. A multivariate regression model was designed to define the most significant variable
which affected the pregnancy rate in patients with PCOD.
Results: The prevalence of BV was significantly higher in infertile than fertile women (45.5% vs 15.4%).
The highest prevalence was found in patients with PCOD (60.1%) and unexplained infertility (37.4%). The
CPR in both patients with PCOD and unexplained infertility were significantly higher in the patients who
were treated for BV. Regression model showed that BV was one of the significant factors interfering with
pregnancy.
Conclusions: BV is strongly implicated in female infertility and is probably an underestimated cause of
unexplained infertility. Screening and treatment of BV in patients with PCOD and unexplained infertility
improved the pregnancy rate considerably.