Sperm chromatin structure is associated with the quality of spermatogenesis in infertile patients.

Objective: To establish the diagnostic value of sperm chromatin structure assessment for the evaluation of male factor infertility, in addition to conventional andrological workup.

Design: Cross-sectional controlled study.

Setting: A tertiary referral andrology clinic.

Patient(s): Two hundred seventy-nine male partners of infertile couples.

Intervention(s): None.

Main Outcome Measure(s): The DNA fragmentation index (DFI) determined by the sperm chromatin structure assay (SCSA), semen parameters, serum levels of reproductive hormones, and World Health Organization (WHO) classification of male factor subfertility.

Result(s): In all patient categories, except those including patients with hypogonadotrophic hypogonadism, sperm antibodies, or normospermia, DFI was significantly higher compared with in proven fertile controls. After classification of the quality of spermatogenesis based on mean testicular volume (<10 ml vs. >15 ml), follicle stimulating hormone (FSH; > 10 U/L vs. <5 U/L), and inhibin-B (<100 nmol/L vs. >150 nmol/L), the DFI was significantly higher in patients with poor spermatogenesis (35.9%) than in patients with normal spermatogenesis (25.9%). In a multiple regression analysis, the teratozoospermia index, sperm vitality, and FSH were significant determinants of the DFI level. Male age was associated with DFI, but leukocytospermia, body mass index, and smoking were not confounders of DFI.

Conclusion(s): Impaired spermatogenesis, irrespective of the WHO classification of male factor subfertility, is generally associated with an increase of sperm DNA damage.