Background: Asthenozoospermia (AZS), characterized by reduced or absent sperm motility in fresh ejaculates, is a leading cause of male infertility. Sperm freezing, an integral part of assisted reproductive technologies helps preserve male fertility but often compromises sperm quality. Theophylline, a xanthine derivative with antioxidant properties, functions as a phosphodiesterase inhibitor, enhancing intracellular cyclic adenosine monophosphate (cAMP) levels and cAMP-dependent processes like sperm motility. While theophylline has shown promise in improving viable sperm quality, its effect on sperm freezing in AZS individuals remains unclear. Objective: This study aimed to evaluate the effect of theophylline on sperm parameters during the freezing- thawing process in AZS men. Materials and Methods: In this experimental study, 30 semen samples from AZS men referred to the Roya infertility treatment center at Qom University Jihad, Qom, Iran were collected into sterile containers through masturbation in 2023-2024. Each sample was divided into 3 groups: control (fresh semen), freeze (frozen with cryoprotectant only), and freeze + theophylline (frozen with cryoprotectant supplemented with 0.05 mM theophylline). Cryopreservation was performed using a human sperm-freezing medium and a rapid freezing method. Sperm motility, viability (assessed via eosin- nigrosin staining), and morphology (evaluated using the Diff-Quick Kit) were analyzed according to World Health Organization criteria. Results: The freeze-thaw group showed a significant reduction in the mean percentages of sperm motility, viability, and normal morphology compared to the control group (p = 0.001). In contrast, the freezing + theophylline group demonstrated a significant increase in sperm motility and viability (p = 0.001) and an increase in normal morphology (p = 0.035) compared to the freezing group. Conclusion: This study demonstrated that supplementing the cryoprotectant medium with theophylline significantly improves sperm motility, viability, and morphology in AZS men, emphasizing its potential to reduce cryopreservation damage and enhance fertility outcomes in assisted reproductive technologies.
