Can we predict oocyte maturation prior to denudation for intracytoplasmic sperm injection?

Intracytoplasmic sperm injection (ICSI) was introduced in 1992 as a method to treat couples with severe male infertility. However, in the last two decades, the use of ICSI has increased substantially even among patients without male factor infertility. In ICSI the oocytes are scrutinized for maturity upon insemination and the immature oocytes are discarded. The aim of the present study was to assess the ability of an experienced embryologist to identify the maturity of the oocytes prior to their denudation. In the present prospective observational study, four experienced embryologists examined the oocytes prior to their denudation and decided whether the oocytes were mature or immature. Later, the oocytes were denudated and the embryologist again examined the oocytes to confirm their prior assumptions. 483 oocytes were examined by four embryologists. Three hundred and fifty one of the oocytes were mature (72.7%) and 132 were immature (27.3%). The embryologists were able to correctly identify oocytes maturation status in 85.3% of cases. The embryologists were able to correctly identify 90% of the mature oocytes and 72.7% of the immature oocytes. When they assumed that the oocytes were mature they were correct in 89.% of the cases, while only 74.6% of their prediction that the oocytes were immature were true. To conclude, the embryologists are able to identify the oocytes maturation status before denudation at the majority of the cases. Whenever the oocytes are suspected to be immature, further consideration should be made whether to proceed to ICSI or not.