Prevalence of Genital Tract Infections and Microbiota Disturbances in Infertile Women: Implications for Reproductive Health

Infertility affects 10–15% of couples globally, with female factors contributing to nearly half of all cases.^1^ In low- and middle-income countries, the burden is higher due to untreated reproductive tract infections, limited access to assisted reproductive technologies (ART), and sociocultural stigma. ^2^

Classical causes of female infertility include ovulatory dysfunction, tubal factor infertility, endometriosis, and uterine abnormalities. However, in the past decade, increasing evidence implicates alterations in the vaginal microbiota and asymptomatic genital infections in subfertility and ART failure. ^3^

A healthy vaginal environment is typically dominated by Lactobacillus spp., which produce lactic acid and hydrogen peroxide, maintaining a pH <4.5.^4^ Dysbiosis leads to bacterial vaginosis (BV), characterized by overgrowth of anaerobes such as Gardnerella vaginalis and Atopobium vaginae, resulting in elevated vaginal pH and inflammatory cytokines that impair implantation and increase miscarriage risk.^5,6^

Sexually transmitted infections (STIs), particularly Chlamydia trachomatis and Mycoplasma genitalium, are strongly linked with pelvic inflammatory disease (PID), tubal scarring, and infertility.^7^ Molecular diagnostic studies reveal that conventional cultures often underestimate the prevalence of these pathogens, underscoring the need for PCR-based screening.^8^

Fungal and protozoal pathogens also contribute. Candida albicans colonization disrupts epithelial integrity, while Trichomonas vaginalis infection has been associated with cervicitis, vaginal inflammation, and reduced sperm survival.^9,10^

The emergence of antimicrobial resistance (AMR) among genital pathogens is an additional challenge. ESBL-producing E. coli and fluoroquinolone-resistant Klebsiella and Pseudomonas spp. have been reported in Indian cohorts, limiting treatment options.^11,12^

This study was conducted to: (i) identify microbial isolates in infertile women, (ii) analyze symptomatic versus asymptomatic distribution, (iii) estimate prevalence of Candida and Trichomonas, and (iv) assess ESBL production and AMR patterns. Our findings provide insights for integrating microbiota assessment into infertility management.v

This prospective observational study was conducted over two years in the Department of Microbiology at a tertiary care hospital in India.

Sample Size: 246 infertile women aged 16–37 years.

Inclusion Criteria:

• Women with primary or secondary infertility (failure to conceive after ≥12 months of unprotected intercourse).
• Willingness to provide vaginal/cervical swabs.
• Age 16–37 years.

Exclusion Criteria:

• Recent antibiotic use (within 4 weeks).
• Prior diagnosis of uterine/tubal abnormalities or endometriosis.
• Previous pelvic inflammatory disease (PID).
• Systemic illness (e.g., diabetes, HIV).
• BMI >30 kg/m².

Specimen Collection: Vaginal and cervical swabs were collected aseptically.

Laboratory Processing:

• Microscopy: Wet mount (saline/KOH), Gram staining for bacterial morphotypes, clue cells, yeast.
• Culture: Nutrient agar, blood agar, MacConkey agar, Sabouraud agar for fungi.
• Molecular Testing: PCR for Chlamydia trachomatis, Mycoplasma hominis, M. genitalium, and Ureaplasma spp.
• AST: Kirby–Bauer disc diffusion on Mueller–Hinton agar per CLSI 2021 guidelines. ESBL confirmed by combined disc method.

Statistical Analysis: Data analyzed using SPSS v26. Continuous data reported as mean ± SD; categorical data as frequency (%). Results presented in seven tables with interpretations.

Mean age ~29 years, ~31% symptomatic, showing infections are not always clinically evident.

Figure 1. Demographic and Clinical Characteristics (n=246)

Figure 2. Frequency of Microbial Isolates in Females

Asymptomatic infections predominate (~two-thirds).

Figure 3. Symptomatic vs Asymptomatic Distribution

Figure 4. Candida Prevalence

Figure 5. Trichomonas Prevalence

Figure 6. ESBL-Producing Organism

Figure 7 :Antibiotic sensitivity pattern for gram negative isolates in women

This study highlights the significant contribution of genital tract infections and microbial dysbiosis to female infertility. Culture positivity (62.2%) aligns with prior Indian studies reporting 55–65% positivity.^13,14^ Importantly, asymptomatic infections comprised 64%, underscoring the limitations of symptom-based screening.^15^

Our microbial spectrum was dominated by S. aureus, E. coli, and Candida albicans. Similar findings have been reported in Indian cohorts, where these organisms accounted for the majority of genital tract isolates in infertile women.^16,17^ Globally, BV-associated pathogens (Gardnerella, Atopobium) and STIs (Chlamydia, Mycoplasma) are also frequent, but limited PCR testing may underestimate their prevalence in this study.^18^

Candida prevalence (5.7%) matches prior reports of 5–8% in infertile women.^19^ Trichomonas vaginalis prevalence (3.3%) is slightly lower than African data (5–7%), but consistent with Indian studies (2–4%).^20^ Both pathogens contribute to vaginal inflammation, altering pH and reducing sperm survival.

AMR patterns are concerning. Half of E. coli isolates were ESBL producers, mirroring national surveillance data showing >40% ESBL rates in community uropathogens.^21^ Resistance in Acinetobacter (37% ESBL) further emphasizes the growing threat of MDR organisms. Such resistance reduces efficacy of cephalosporins and necessitates reliance on carbapenems, which may not be sustainable in resource-limited settings.^22^

Our findings align with previous studies demonstrating that asymptomatic infections compromise ART outcomes by impairing implantation and increasing miscarriage risk.^23^ Partner management is crucial, as reinfection cycles perpetuate colonization and treatment failure.^24^

Limitations: Culture-based methods under-detect fastidious organisms; lack of longitudinal outcome data prevents correlation with conception rates. Future studies using next-generation sequencing (NGS) could delineate complete microbiota profiles and clarify causal relationships.

Implications: Integration of routine microbiota and AMR screening in infertility workups, along with partner-inclusive treatment strategies, can reduce ART failures and improve reproductive outcomes.

Female infertility in this cohort was strongly associated with asymptomatic infections. Routine screening for microbiota disturbances and AMR patterns, coupled with partner-based management, is essential for improving fertility outcomes

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