Endometrial Microbes, Systemic Inflammatory Markers, and In Vitro Fertilization Outcomes Among Infertile Women: A Cross-Sectional Study.

Background and objectivesInfertility among couples of the reproductive age group is a global healthcare concern. Imbalance in the neuro-immune-endocrine network leads to altered pro- and anti-inflammatory markers and endometrial dysbiosis. These two factors collectively cause infertility, despite the advancements in in vitro fertilization (IVF). Indian studies exploring this aspect are scarce. Therefore, we planned to evaluate endometrial microbes, interleukin-10 (IL-10), and IL-17 among infertile women seeking IVF.MethodsThis cross-sectional study was conducted from January 2025 to June 2026 at Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar, India. Infertile women aged 31-40 years seeking treatment with IVF were included in this study. Those with active vaginal or cervical infection, any autoimmune disease, or use of antimicrobials, corticosteroids, or immunosuppressive agents were excluded. The endometrial and blood samples were obtained in the peri-implantation window. Cultivable isolates were identified using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS; BioMérieux, France). Serum IL-10 and IL-17 levels were detected using enzyme-linked immunosorbent assay (ELISA). We used R software (version 4.6.2) for data analysis.ResultsOur study population comprised 50 infertile women. The study population's median age was 37 (35-38) years. The median body mass index (BMI) of the study participants was 26.75 (24.20-30.80) kg/m2. Of the study participants, 32 (64%) had primary infertility. Of the 50, 17 (34%) had a tubal cause of infertility. Lactobacillus spp. (23, 46%) was the most common microbe in the endometrial cultures, followed by Enterococcus faecalis (5, 10%) and Klebsiella pneumoniae (5, 10%). A total of 20 (40%) participants became pregnant following IVF treatment. The remaining 30 (60%) had IVF failure. The median IL-10 values for participants with IVF failure and success were 14.93 (13.87-15.96) pg/mL and 35.60 (32.53-39.94) pg/mL, respectively (p < 0.001). The corresponding median IL-17 values were 40.02 (34.84-44.29) pg/mL and 23.57 (21.06-24.36) pg/mL (p < 0.001). The 20 participants who were pregnant with IVF had lower IL-17 levels and higher IL-10 levels. The differences were statistically significant. The IVF success rates were seen among those aged 31-35 years (8 of 15, 53.3%), secondary infertility (9 of 18, 50%), those with Lactobacillus spp. (14 of 23, 60.9%), and those with previous abortion (13 of 28, 46.4%).ConclusionThe commonest microbe in the endometrial cultures was Lactobacillus spp. Of the 20 participants with successful IVF, two-thirds had positive endometrial cultures for Lactobacillus spp. We also found that higher IVF success rates were seen among those with secondary infertility and aged between 31 and 35 years. Participants with IVF failure had higher IL-17 levels and lower IL-10 levels.