Environmental and Lifestyle Exposures and Male Factor Subfertility Proportion Among Infertile Couples: A Clinic-Based Multicenter Cross-Sectional Analysis from Indian Male Factor Subfertility Evaluation (IM-FaST) Study.

Male factor subfertility is a significant public health issue and contributes substantially to the overall burden of infertility. The present study evaluated environmental and lifestyle exposures among male partners of infertile couples across India, estimated the proportion of male factor subfertility, and examined associated semen parameter abnormalities. This multicentric, cross-sectional study involved male partners of infertile couples presenting to 17 tertiary centres across India. Socio-demographic, occupational, lifestyle, and clinical data were collected using structured questionnaires and clinical examinations. Semen analysis was performed according to the WHO-2021 guidelines. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. Among 2414 infertile couples, 77.5% had primary infertility and 22.5% secondary infertility. Male factor subfertility accounted for 27.3% of cases, female factor 36.9%, combined factors 9.7%, and unexplained infertility for 26.1%. Asthenozoospermia (23.4%) was the most common semen abnormality. Multivariate analysis identified urban residence (p = 0.02), semiskilled occupation (p = 0.009), lower socioeconomic status (p = 0.013), heat exposure (p = 0.002), over-the-counter drug use (p = 0.03), previous genital tract surgery (p = 0.011), and COVID-19 infection (p = 0.014) as independent predictors of abnormal semen parameters. Varicocele and congenital genital tract anomalies demonstrated increased odds of abnormal parameters but did not reach statistical significance (p = 0.067; p = 0.056, respectively). However, the increasing severity of varicocele showed a significant negative correlation with sperm concentration per mL (p = 0.001) and percentage of morphologically normal sperm (p = 0.040). Male factor subfertility in India is multifactorial, strongly influenced by modifiable environmental, lifestyle, and clinical factors.