P-482 Bacterial vaginosis in a subfertile population undergoing fertility treatments: a prospective cohort study

Abstract

Abstract Study question Does bacterial vaginosis (BV) influences pregnancy rates during fertility treatments? Summary answer BV does not significantly impact ongoing pregnancy or live birth rates but could affect miscarriage rates. What is known already BV is known to influence several obstetric outcomes, such as preterm delivery and endometritis. Only few studies investigated the effect of BV in subfertile women, and studies found a negative effect of BV on fecundity especially in the in vitro fertilisation (IVF) population. Study design, size, duration Observational prospective study, 76 couples attending a fertility clinic in the Netherlands between July 2019 and June 2022, undergoing a total of 133 attempts of intra uterine insemination (IUI) or IVF. Participants/materials, setting, methods Participants undergoing IUI, IVF or intra cytoplasmatic sperm injection (ICSI). Vaginal samples taken at oocyte retrieval or insemination were analysed on qPCR BV and 16S rRNA gene microbiome analysis of V1-V2 region. Logistic regression with a Generalized Estimated Equations (GEE) analysis was used to account for multiple observations per couples. Main study outcome was defined as ongoing pregnancy at 12 weeks. Secondary outcomes were miscarriage rate and live birth rate. Main results and the role of chance A total of 26% of the 133 samples tested positive for BV. No significant differences were observed in ongoing pregnancy or live birth rates based on BV-status (OR 0.50 (0.16-1.59), aOR 0.32 (0.09-1.23)) or microbiome community state type (CST). There was a tendency of more miscarriages based on positive BV status (OR 4.22 (1.10-16.21), aOR 4.28 (0.65-28.11)) or microbiome CST group III/IV. Sample outcomes of qPCR BV were in accordance with their microbiome analyses. On baseline groups significantly differed on smoking status and body mass index (BMI). Odds ratios were adjusted for smoking status, BMI and socioeconomic status. Limitations, reasons for caution Numbers of the initial sample size calculation were not met. Therefore, numbers may be too small to draw firm conclusions. Wider implications of the findings This study describes the influence of BV or an abnormal microbiome in a subfertile population undergoing fertility treatments. A possible effect of lifestyle factors on BV-status is shown. Combining qPCR and microbiome results and analysing both IUI and IVF/ICSI treatments can contribute to better generalisability to the consulting room. Trial registration number Z21.031