P-295 Impact of Nugent score and microbiota on live birth rate after fresh embryo transfer in women with endometriosis? A tool not to be neglected

Abstract Study question Do altered vaginal microbiota, and vaginal leukocytosis, both estimated by the Nugent score, influence live birth rates in IVF after a fresh embryo transfer in women with endometriosis? Summary answer Nugent score is able to diagnose Bacterial Vaginosis and predicts its bad influence in live birth rates after fresh embryo transfer in women with endometriosis. What is known already For several years, special attention has been given to vaginal microbiota and vaginosis as part of IVF and embryo implantation failure. Lactobacillus is recognized as dominant in a healthy vaginal microbiota environment while gardnerella is more present in a vaginal microbiota altered and bacterial vaginosis. While all published studies are mostly meta-analysis, the originality of our study is the number of patients with endometriosis (223) tested in a single laboratory and taken care of by one center only. This study also reports the influence of the microbiota (gardnerella especially) and leucocytosis on LBR in case of endometriosis. Study design, size, duration This study is a retrospective, a non-interventional monocentric cohort study conducted between January 2017 and December 2019. 223 patients with endometriosis benefited from Nugent score for bacterial vaginosis before the start of treatment or within the first week of injections for IVF protocol. No patient was treated by antibiotics before the swab. Participants/materials, setting, methods Nugent score is Gram stained scoring (scale of 0 to 10) of bacterial morphotypes from vaginal smear samples calculated according to recommendations. Scores of 0-3 (Group 1) indicates normal flora, scores of 4-6 (Group 2) is considered intermediate flora and scores of 7-10 (Group 3) is diagnosed Bacterial Vaginosis (BV) (Nugent et al., 1991). In the same way, presence and abundance ok leukocytes were recorded Main results and the role of chance BV in endometriosis population is of 8.07% (18/223), There is no difference between the three Nugent groups regarding demographics criteria. Concerning microbiota per se the presence of Lactobacillus is depending of age and it is statistically more represented in older patients (p = 0.04) while the presence of gardnerella is depending of indication. Gardnerella is more represented in tubal indications and the difference is statistically significative (p = 0.01). Concerning leukocytosis (numerous, relatively numerous and few leukocytes) or no (rare leukocytes) the differe