Characterization of the injection funnel during intracytoplasmic sperm injection reflects cytoplasmic maturity of the oocyte

Oocyte maturation within the follicle is closely associated with a remarkable change in cytoplasm viscosity from an aqueous to a more viscous subtype. Precise evaluation of the injection funnel may help to explain deviations from expected ICSI outcome and could also assist in optimizing controlled ovarian hyperstimulation.