Longitudinal analysis of vaginal microbiota during IVF fresh embryo transfer and in early pregnancy

Non-Lactobacillus-dominated vaginal microbiota has been associated with poor gynecologic health and complications during pregnancy. Lactobacilli and especially L. crispatus associate with good reproductive health and dominate the microbiota during healthy pregnancy. We examined whether the composition of vaginal microbiota at the time of fresh embryo transfer (ET) has an impact on the success of in vitro fertilization (IVF) and whether vaginal microbiota changes from IVF-ET to early pregnancy within individuals