The uterine and vaginal microbiome in assisted reproductive technologies: implications for maternal and offspring...

Assisted reproductive technologies (ART) have provided significant advancements in infertility treatment. Despite this, ART-conceived pregnancies are also associated with higher risks for adverse maternal and offspring outcomes. Recent evidence highlights the role of the reproductive tract microbiome (mainly the vaginal and endometrial microbiome) in implantation success and gestational physiology. The purpose of this review is to summarize the state of knowledge pertaining to the content, function, and disruption of the uterine and vaginal microbiome in ART contexts and to consider the adverse effects of changing the microbiome on maternal health, pregnancy outcomes, and development of progeny.

A narrative synthesis of the literature covering the period 2005-2025 was undertaken using the PubMed, Scopus, and CINAHL databases. Articles addressing microbiome changes associated with ART and reproductive outcomes were included.

ART procedures such as vaginal antisepsis, oocyte retrieval, embryo transfers, hormone stimulation, and use of prophylactic antibiotics have caused observable disruptions to the reproductive tract microbiome. The loss of Lactobacillus dominance and the development of dysbiosis are linked with lower implantation rates, a higher incidence of gestational disorders, such as preeclampsia and gestational diabetes, a heavy risk of preterm delivery, and an increased risk of adverse neonatal outcomes, such as altered immune development and developmental delay. Furthermore, newer alternatives including probiotics, individual microbiome testing, and multi-omic platforms show promise, but are limited by variability in clinical approaches and a lack of empirical backing.

The uterine and vaginal microbiome profoundly impact ART outcomes by modulating implantation, immune tolerance, and fetal development. Integrating microbiome-informed diagnostics and therapies into fertility treatments offers a new frontier in precision reproductive medicine.