Comparing the different methods of sperm chromatin assessment concerning ART outcomes

Sperm DNA fragmentation and maturation directly interferes with reproductive efficiency. Although there are several methods for assessing sperm DNA integrity, however, many of them are laborious and require high-precision equipment in the clinics. Thus, evaluating economic and reliable methods to prepare suitable sperm for assisted reproductive technologies without DNA damage is critical.

A total of 114 semen samples were collected and analyzed using computer-assisted semen analysis. The DNA fragmentation index (DFI) of all samples was evaluated by two methods of sperm chromatin dispersion (SCD) and sperm chromatin structure assay (SCSA). Besides, chromatin maturation index (CMI) was assessed by three methods including aniline blue (AB)-sperm chromatin maturation assay (SCMA), fluorescence microscopic chromomycin A3 (fmCMA3), and flow cytometric CMA3 (fcCMA3).

The result showed that the DFI had no statistically significant differences (p>0.05) between SCSA (26.98%±1.28%) and SCD (27.88%±1.278%), although SCD demonstrated a strong correlation with DNA maturity (p<0.001), which had not been seen in SCSA. Besides, the CMI demonstrated significant differences (p<0.001) when assessed by AB-SCMA (14.86%±0.65%), fmCMA3 (29.18%±1.01%), and fcCMA3 (22.45%±0.62%). Among these, only the fmCMA3 showed a significant correlation with semen parameters (p<0.01) and embryo development (p<0.001).

It seems that SCD and fmCMA3 were more accessible, affordable, and reliable tests for assessing DFI and CMI. It appeared these two methods may be the best choices for evaluating sperm DNA integrity in clinics.