Non-invasive characterization of oocyte deformability in micro-constrictions

Oocytes naturally present mechanical defects that hinder their development after fertilization. Thus, in the context of assisted reproduction, oocyte selection based on their mechanical properties has great potential to improve the quality of the resulting embryos and the success rate of these procedures. However, the use of mechanical properties as a quantifiable selective criterion requires robust and non-destructive measurement tools. This study developed a constriction-based microfluidic device that monitors the deformation of mouse oocytes under controlled pressure. The device can distinguish mechanically aberrant oocyte groups from healthy control ones. Based on a mathematical model, we propose that deformability measurements infer both oocyte tension and elasticity, elasticity being the most discriminating factor in our geometry. Despite force transmission during oocyte deformation, no long-term damage was observed. This non-invasive characterization of mouse oocyte deformability in micro-constrictions allows for a significant advance in assessing the mechanical properties of mammalian oocytes and has potential application as a quantifiable selective criterion in medically assisted reproduction. TeaserA measurement method for translating advances in oocyte mechanics into selection criteria for improving medically assisted reproduction.