Inhibin B/FSH Ratio as a Predictor of Testicular Pathology in NOA

This retrospective observational study evaluated the diagnostic and predictive value of serum Inhibin B (INHB), follicle-stimulating hormone (FSH), and the INHB/FSH ratio in differentiating histopathological subtypes of non-obstructive azoospermia (NOA) in men undergoing microdissection testicular sperm extraction (micro-TESE). Seventy-three patients treated at a single tertiary referral center between January 2023 and September 2025 were included. Hormonal parameters were assessed preoperatively, and histopathological findings were categorized into five groups (SCOS, EMA, LMA, HSG, NS). The INHB/FSH ratio demonstrated significant discriminative ability across histopathological patterns and showed strong predictive performance in ROC and regression analyses. These findings suggest that the INHB/FSH ratio may serve as a practical, non-invasive biomarker for estimating testicular pathology severity in NOA patients.

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Key information

Conditions

Azoospermia, Nonobstructive Non-obstructive Azoospermia

Age range

18 year and older

Sex eligibility

Male

Study type

Observational

Primary location

Elazığ Fethi Sekin City Hospital

Elâzığ, 23100, Turkey (Türkiye)

About this study

Non-obstructive azoospermia (NOA) represents a severe form of male infertility characterized by impaired spermatogenesis. Although microdissection testicular sperm extraction (micro-TESE) remains the gold standard for sperm retrieval in these patients, predicting underlying histopathology before surgery remains clinically challenging. Identifying reliable non-invasive biomarkers may improve patient counseling and optimize surgical decision-making.

This retrospective observational study was conducted at Elazığ Fethi Sekin City Hospital, Türkiye. Medical records of men diagnosed with NOA who underwent micro-TESE between January 2023 and September 2025 were reviewed. Patients with obstructive azoospermia, known endocrine disorders, or incomplete clinical data were excluded.

Preoperative serum levels of FSH, luteinizing hormone (LH), total testosterone, and Inhibin B were measured within three months prior to surgery using standardized immunoassay methods. The INHB/FSH ratio was calculated for each patient.

Histopathological evaluation of testicular tissue samples obtained during micro-TESE was performed by an experienced pathologist blinded to hormonal results. Patients were categorized into five histopathological groups: Sertoli Cell-Only Syndrome (SCOS), Early Maturation Arrest (EMA), Late Maturation Arrest (LMA), Hypospermatogenesis (HSG), and Normal Spermatogenesis (NS).

The primary outcome measure was the association between the INHB/FSH ratio and histopathological classification. Statistical analyses included descriptive statistics, non-parametric group comparisons, receiver operating characteristic (ROC) curve analysis to determine discriminative performance, and multivariable regression models to evaluate predictive relationships.

This study aimed to clarify whether the INHB/FSH ratio could serve as a clinically useful marker for estimating testicular pathology severity in men with NOA undergoing micro-TESE.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Male patients who underwent micro-TESE for non-obstructive azoospermia
Available histopathological evaluation of testicular tissue
Available preoperative serum hormone measurements (FSH, LH, testosterone, Inhibin B)

Exclusion criteria

• Obstructive azoospermia

Incomplete clinical, hormonal, or histopathological data
Previous testicular malignancy
History of chemotherapy or radiotherapy affecting spermatogenesis

Treatment and study plan

Primary outcomes

Micro-TESE Sperm Retrieval Outcome

Time frame: During micro-TESE procedure (intraoperative assessment)

Successful sperm retrieval defined as the presence of spermatozoa on microscopic examination, and its association with histopathological classification and serum hormone levels.

Sponsors and collaborators

Lead sponsor

Elazıg Fethi Sekin Sehir Hastanesi

Other

Registry information

Official study title

The Predictive Value of Serum Inhibin B/FSH Ratio in Estimating Pathology Results in Patients Undergoing Micro-TESE Due to Azoospermia

Important dates

Study start: 2026
Primary completion: 2026
Study completion: 2026
First posted: Feb 17, 2026
Registry last updated: Feb 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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