DNA fragmentation in spermatozoa: a historical review

Area of Science:

• Reproductive Biology
• Genetics
• Clinical Andrology

Background:

• Sperm DNA fragmentation research spans over 70 years, starting with discoveries in sperm nuclear structure.
• Early studies linked unstable chromatin to subfertility, with DNA damage impact investigated in the 1970s.
• Sperm DNA fragmentation was introduced as a concept related to infertility in the 1980s, alongside initial testing methods like the Sperm Chromatin Structure Assay (SCSA).

Observation:

• The association between sperm DNA fragmentation and pregnancy loss has been extensively studied, highlighting the need for therapeutic interventions.
• Novel methods like cell sorting and hyaluronic acid (HA) binding are emerging, but their clinical value requires further elucidation.
• Despite significant research, sperm DNA fragmentation testing is not routinely used in fertility clinics due to various underlying causes.

Findings:

• The abundance of diverse testing methods has hindered the establishment of a clinically significant threshold for sperm DNA fragmentation.
• While some promising methods exist, commercialization has limited accessibility to larger laboratories.
• Numerous reviews and meta-analyses exist, but often use varied assays, ART protocols, outcome definitions, and small patient cohorts.

Implications:

• Standardization of sperm DNA fragmentation assays is crucial for reliable clinical application.
• Further research focusing on clinical implementation is necessary to integrate this relevant analysis into routine fertility care.
• Addressing the lack of standardized thresholds and improving accessibility of validated methods are key to advancing reproductive medicine.