Comparative Study of the Effect of Sperm-Cryoprotectant Media on Post-Freezing Sperm Quality in Oligoasthenoteratozoospermia (OAT) Males
Vinayanuvattikhun N, MD1, Tanprasertkul C, MD,PhD1,2, Somprasit C, MD1, Chiya J, BSc3, Boonyarangkul A, MD1
Affiliation : 1 Department of Obstetrics and Gynecology, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand 2 Center of excellence in Applied Epidemiology, Thammasat University, Pathum Thani, Thailand 3 Thammasat Fertility Center, Thammasat University Hospital, Pathum Thani, Thailand
Background : Sperm cryopreservation is one of the important processes of reproductive technology. Because of the nature of the
frozen-thawed process, the sperm are subject to being damaged in its structure and function after the thaw, especially in men who
have shown an abnormal sperm-analysis result. They are more likely to have damaged sperm DNA as compared to normozoospermia
men.
Objective : The present study aims to compare the efficiency of the sperm cryoprotectant media with four types of complex
cryoprotectant agents (or CPA, namely GEYC, SF, TYB, and HSPM) to prevent sperm DNA damage in men who have
oligoasthenoteratozoospermia (OAT).
Materials and Methods : Semen samples of the 50 OAT men were divided into 5 groups, namely group 1: prior-freezing sperm
(Control), group 2: frozen sperm by glycerol egg yolk citrate (GEYC), group 3: frozen sperm by Sperm freeze (SF), group 4: frozen
sperm by TEST-yolk-buffer (TYB) and group 5: frozen sperm by human sperm preservation medium (HSPM). The dissolved
sperm was evaluated by sperm quality, as measured in the percentage of sperm motility, normal sperm morphology, vitality, and
sperm DNA damage. The data consisted of a comparison between sperm before freezing and sperm in each of the frozen-thawed
groups.
Results : The comparison of the frozen sperm (in groups 2, 3, 4 and 5) with the control group showed that the percentage of sperm
motility, normal sperm morphology, and sperm vitality had significantly decreased. Furthermore, the rate of sperm DNA damage
had significantly increased in the frozen sperm. When comparing the dissolved sperm properties between the four groups of CPAs,
there was no difference in sperm vitality, motility, and normal sperm morphology. In terms of sperm DNA damage, the sperm in the
GEYC and SF groups had less DNA damage than in the HSPM and TYB groups. However, there was no statistically significant difference
between the GEYC and SF groups regarding DNA damage.
Conclusion : In the infertile men who have OAT, freezing sperm with GEYC or SF helps to reduce sperm DNA damage, as compared
with sperm that has been frozen by HSPM and TYB. The research data suggest that sperm of infertile men who have OAT should be
frozen using the cryoprotectant composed of egg yolk because of its ability to reduce sperm DNA damage when taken from the
freezing procedure.
Keywords : Oligoasthenoteratozoospermia, Sperm cryopreservation, Sperm DNA damage
