Low concentration of hyaluronidase for oocyte denudation can improve fertilization rates and embryo quality.

Objective: Hyaluronidase enzyme is an extremely important factor for the process of oocyte denudation, but little is known about its negative effects.

Methods: This prospective randomized study analyzed the results of using different concentrations of hyaluronidase (Diluted: 8IU/mL and Normal: 80IU/mL) used for denudation of sibling-oocytes for 22 women undergoing treatment for assisted reproduction by ICSI. A total of 192 oocytes were injected, being 104 for group I (diluted) and 88 for group II (normal).