High Variability in Human Sperm Membrane Potential over Time Can Limit Its Reliability as a Predictor in ART...

Area of Science:

• Reproductive biology
• Sperm physiology
• Assisted Reproductive Technology (ART)

Background:

• Sperm membrane potential (Em) hyperpolarization during capacitation is a key indicator of fertilizing ability.
• Em has been proposed as a predictive biomarker for in vitro fertilization (IVF) success.
• The temporal stability of Em and its reliability for advance ART decision-making remain unclear.

Purpose of the Study:

• To evaluate the temporal consistency of human sperm Em within individuals.
• To assess Em's utility as a prognostic marker when measured days or weeks before IVF.
• To determine if Em can reliably guide ART decisions in advance.

Main Methods:

• Assessed Em in capacitated and non-capacitated sperm from normospermic donors over 28 days.
• Utilized a fluorometric assay for Em measurement.
• Analyzed intra-donor Em variability and coefficients of variation (CV), comparing capacitated values to a -48.6 mV fertilization threshold.

Main Results:

• Significant intra-donor Em variability over time was observed (p = 0.007).
• Approximately 50% of donors crossed the functional threshold across different measurement sessions.
• Capacitated sperm showed greater variability (CV > 30% in several donors) than non-capacitated sperm.

Conclusions:

• Temporal variability in Em undermines its reliability for advance ART decision-making.
• Em is a promising functional marker when assessed on the day of IVF.
• Further research is needed to identify factors influencing Em stability for improved ART prognostication.