Does dysbiotic endometrium affect blastocyst implantation in IVF patients?

Area of Science:

• Reproductive endocrinology and infertility
• Microbiome research
• Genetics and genomics

Background:

• The endometrial microbiome plays a crucial role in successful embryo implantation.
• Understanding the relationship between endometrial bacterial profiles and in vitro fertilization (IVF) outcomes is essential.
• Dysbiosis, an imbalance in microbial communities, has been implicated in infertility.

Purpose of the Study:

• To investigate pregnancy outcomes in IVF patients with eubiotic versus dysbiotic endometria at embryo transfer.
• To identify specific endometrial bacterial profiles conducive to successful embryo implantation.

Main Methods:

• Ninety-nine IVF patients under 40 undergoing vitrified-warmed blastocyst transfer were analyzed.
• Endometrial microbiome analysis was performed concurrently with mock embryo transfer.
• Bacterial genus-level profiles and Lactobacillus percentage were assessed.

Main Results:

• 31.3% of patients presented with dysbiotic endometria.
• Pregnancy and miscarriage rates were similar between eubiotic and dysbiotic groups.
• Atopobium, Gardnerella, and Streptococcus were common in dysbiotic endometria; some achieved pregnancy with 0% Lactobacillus.

Conclusions:

• Species-level microbiome analysis may be required to identify pathogenic bacteria accurately.
• Avoid over-treatment of non-Lactobacillus bacteria.
• Further studies are needed to elucidate the impact of pathogenic bacteria on embryo implantation.