Etiological Factors of Azoospermia in a Fertility Center in Eastern India

Introduction: Azoospermia is a major contributory factor to male infertility, with varied underlying etiologies that require structured evaluation to guide management.In India, epidemiological data on the causes of azoospermia, particularly from specialized fertility centers, remain limited.Understanding the distribution of obstructive and nonobstructive causes is critical for optimizing diagnostic strategies and treatment sequencing in resource-constrained settings.Aims and objectives: To identify and analyze the most common etiological factors of azoospermia among patients attending a fertility center in Eastern India, with particular focus on nonobstructive azoospermia (NOA) and its idiopathic subset, including the role of genetic and hormonal assessment.Materials and methods: This retrospective study included 1,200 azoospermic male patients evaluated at the Genome Fertility Centre, Kolkata, over a defined period.Clinical evaluation, hormonal profiling, scrotal ultrasound, and semen analysis were performed routinely.Some patients underwent karyotyping based on clinical suspicion and biochemical abnormalities, whereas others were lost to follow-up.Cases with inconclusive biochemical and genetic findings were categorized as idiopathic.Results: Among the 1,200 subjects, NOA was the predominant category (n = 750; 62.5%), followed by obstructive azoospermia (n = 300; 25%) and hypogonadotropic hypogonadism (HH) (n = 150; 12.5%).Within the NOA group, idiopathic azoospermia represented the largest subgroup (n = 420; 56%).Among these idiopathic cases, 240 (57.1%) had normal hormonal and karyotype results, while 180 (42.9%) were categorized as idiopathic due to pending or incomplete evaluations.Chromosomal abnormalities and endocrine dysfunction were identified in a minority of NOA cases.Conclusion: Nonobstructive causes are the leading etiology of azoospermia in this population, with idiopathic NOA constituting over half of these cases.This emphasizes the need for comprehensive genetic and hormonal assessment pathways, improved follow-up, and further research to uncover undetected etiological mechanisms in idiopathic cases.