Semen preparation methods and sperm apoptosis: swim-up versus gradient-density centrifugation technique

Area of Science:

• Reproductive biology
• Andrology
• Sperm preparation techniques

Background:

• Sperm preparation is crucial for assisted reproductive technologies.
• Assessing sperm apoptosis is important for male infertility evaluation.
• Density-gradient centrifugation and swim-up are common sperm preparation methods.

Purpose of the Study:

• To compare the efficacy of density-gradient centrifugation and swim-up in reducing sperm apoptosis.
• To evaluate the impact of these methods on sperm viability and motility recovery.
• To utilize multiparameter flow cytometry for precise sperm analysis.

Main Methods:

• An autocontrolled split-sample study design was employed.
• Semen samples from 62 male partners undergoing infertility investigations were analyzed.
• Sperm apoptosis, viability, and motility were assessed by flow cytometry and optical microscopy before and after preparation.

Main Results:

• Both density-gradient centrifugation and swim-up significantly reduced the percentages of apoptotic and necrotic sperm.
• Swim-up resulted in a higher mean percentage of viable sperm compared to gradient centrifugation.
• Gradient centrifugation achieved significantly higher recovery rates for total motile, progressive motile, and viable sperm.

Conclusions:

• Both sperm preparation methods effectively yield sperm populations with low apoptotic percentages, minimizing risks in clinical applications.
• The selection between gradient centrifugation and swim-up should be guided by the specific requirements of assisted reproductive technology, such as in vitro fertilization/intracytoplasmic sperm injection or intrauterine insemination.
• Viable sperm percentage and progressive motility are key predictors influencing the choice of method.