Value of sperm DNA integrity as a supplementary predictor of male fertility

Objective To evaluate the value of sperm DNA integrity test compared with traditional semen analysis in the supplementary assessment of male fertility. Methods A total of 1076 semen samples were collected at the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University from April to October 2017. Each specimen was divided into two parts for conventional semen analysis and sperm DNA integrity test. Sperm DNA integrity was assessed to be good (DFI≥30%), fair (15%<DFI<30%), or poor (DFI≤15%) according to sperm DNA fragmentation index (DFI). According to the age of the patients, the specimens were divided into three groups: 21-30 years old, 31-40 years old, and ≥40 years old. According to sperm concentration, the specimens were divided into normal (≥15×106/ml) and oligospermia groups (<15×106/ml). According to sperm forward motility rate, the specimens were divided into normal (≥32%) and asthenospermia groups (<32%). The Chi-square test was used to compare the differences in sperm DNA integrity between different groups. Pearson correlation analysis was used to analyze the correlation of patient age, sperm concentration, and forward motility rate with sperm DFI. Results There were significant differences in sperm DNA integrity between the normal and oligospermia groups and between the normal and asthenospermia groups (χ2=96.82, P<0.001; χ2=2.06, P<0.001). Age was positively correlated with DFI (r=0.154, P<0.001), and sperm concentration and forward motility rate were negatively correlated with DFI (r=-0.231, P<0.001). r=-0.564, P<0.001). Conclusion Sperm DFI is negatively correlated with sperm concentration and forward motility rate, and positively correlated with age. Sperm DNA integrity test can make up for the deficiency of semen analysis in evaluating male fertility. Key words: Sperm; DNA; Male; Fertility; Semen analysis; Sperm chromatin structure analysis