Abstract
PURPOSE: Intracellular pH (pH(i)) in sperm cells plays a crucial role in various physiological processes, including motility, capacitation, and fertilization. While previous studies have shown a positive correlation between sperm pH(i) and fertilization success in normozoospermic patients undergoing fertility treatments, its role in non-normozoospermic individuals is unclear. METHODS: This study investigates the relationship between sperm pH(i) and fertilization outcomes in patients undergoing assisted reproduction techniques: in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Qualitative sperm pH(i) evaluation was performed using time-lapse flow cytometry, and both basal pH(i) and pH(i) response capacity (delta pH(i)) were assessed in sperm samples from patients diagnosed with teratozoospermia, asthenoteratozoospermia, or hypoteratozoospermia. RESULTS: Our results revealed significant differences in pH(i) values among diagnostic groups and specific correlation patterns according to the ART used. In ICSI cycles, higher basal pHi values and reduced delta pH(i) were significantly associated with higher fertilization rates in patients with teratozoospermia, while in IVF, the correlations were more variable. CONCLUSIONS: These findings suggest that measuring sperm pH(i) could potentially serve as a valuable tool for predicting fertilization success and guiding treatment decisions during assisted reproduction techniques (ART), contributing to a better understanding of the molecular mechanisms underlying male infertility.