INTRODUCTION
Conventional semen analysis offers limited insights into a man’s reproductive potential and does not always adequately explain male infertility. According to the literature, about 15% of infertile patients have normal sperm parameters. Sperm DNA fragmentation may be one of the causes of male infertility. According to the latest edition of the WHO guideline for the examination and processing of ejaculate (WHO, 2021), the research method and threshold for sperm DNA fragmentation remains in the examination laboratory.
OBJECTIVE
Therefore, the aim of this study was to determine sperm DNA fragmentation threshold for men of North-Western region of Russia.
MATERIAL AND METHODS
A retrospective study of the results of routine sperm analysis and sperm DNA fragmentation rate were performed in 1731 patients from ART department from January 2019 to November 2023. Additionally, the anamnestic data of the patients were analyzed.
RESULTS
Univariate analysis showed that the sperm DNA fragmentation rate dependeds on the patient’s age (p<0.001), the number of days of abstinence (p<0.001), as well as such sperm parameters as motility (p<0.001) and morphology (p=0.002).
To determine the threshold value of the sperm DNA fragmentation, ROC analysis was performed. The sperm DNA fragmentation rate pronounced predictable in relation to the motility (PR <32%) and morphology (< 4%) of spermatozoa. The averaging of the obtained threshold results approaches 15%. Comparative analysis between the results, taking into account the threshold value, showed that the ejaculate volume in the group with sperm DNA fragmentation <15% was statistically lower than in the group ≥15% (3.39±1.54 ml and 3.55±1.5% ml, respectively; p=0.049). The motility and proportion of morphologically normal spermatozoa in the “TUNEL<15%” group were higher (55.8±16% versus 52.9±17.5%; p<0.001; 4.41±3.44% versus 4.07±3.23%; p=0.037). The age of patients and the number of days of abstinence in the “TUNEL<15%” group were lower (36±6.2 years versus 37±6.7; p=0.001; 3.74±1.73 days and 4.12±2.7 days; p=0.006).
CONCLUSIONS
The study showed a relationship between sperm DNA fragmentation and such sperm parameters as morphology and motility. A reference value for the sperm DNA fragmentation rate is provided — 15%.