Effect of sperm storage and selection techniques on sperm parameters

Abstract

Sperm cryopreservation preserves the fertility of cancer patients undergoing chemotherapy, ensures sperm are available at the time of oocyte retrieval in assisted reproductive technology (ART) procedures and avoids the need for repeated sperm extraction surgeries in azoospermic patients. Conventional methods of cryopreservation involve storage in liquid nitrogen (LN 2 ), which causes a significant decline in sperm parameters such as motility and viability and results in DNA damage. Newer methods of sperm cryopreservation such as the LN 2 vapor method, vitrification, and experimental methods such as lyophilization, have significant advantages over the conventional methods in terms of cost effectiveness and ease of use. Density gradient centrifugation (DGC), swim up, and magnetic assisted cell sorting (MACS) can be used prior to or post-cryopreservation to improve post-thaw sperm quality. Cryopreservation in special carriers such as cryoloops and empty zona prevents the loss of small numbers of sperm during cryopreservation. This article will discuss these sperm preservation and selection techniques.

Comparison of semen characteristics and sperm cryopreservation in common marmoset (Callithrix jacchus) and black‐tufted‐ear marmoset (Callithrix penicillata)

“…The freezing strategy proposed here (cryopreservation of semen with TEST egg yolk extender, glycerol at 4% and 6%, and the present freezing protocol) was an attempt to improve the semen cryopreservation protocol, based on previous work with primates, human, and bovine sperm. 15,[38][39][40][41] However, it was unable to preserve sperm quality. All variables-except sperm morphology, presented degradation of semen quality after refrigeration and addition of glycerol and/or thawing.…”

Clinical utility of sperm DNA fragmentation testing: practice recommendations based on clinical scenarios

“…They include: intake of oral antioxidants (111), varicocele ligation (66), frequent ejaculation (112) and sperm selection methods such as magnetic cell sorting (113) or intracytoplasmic morphologically selected sperm injection (114). While varying success rates for these strategies have been reported to reduce SDF, their effect on ART outcomes is still unknown, thus questioning the clinical value of routine application in cases of high SDF before ART (115).…”

Comparison of reproductive outcome in oligozoospermic men with high sperm DNA fragmentation undergoing intracytoplasmic sperm injection with ejaculated and testicular sperm

“…The intake of oral antioxidants (6,7), varicocele repair (8), and the use of recurrent ejaculations before fertilization (9,10) alone or combined with micromanipulation-based sperm selection techniques such as magnetic cell sorting (11,12), physiological ICSI (13), or intracytoplasmic morphologically selected sperm injection (14)(15)(16) have been attempted with varying success rates to decrease SDF. Yet none of these interventions, alone or combined, have been unequivocally proven to be of clinical value to bypass the potential detrimental effect of abnormal SDF on assisted reproductive technology (ART) outcomes (5).…”