Low Oocyte Maturity Rate and Asynchronous Follicle Development: Other Unnoticed Groups in the Bologna Criteria for Poor Responders?

Introduction: This study aimed to evaluate the prognosis of patients with low rates of oocyte maturity and compare those who are aforethought poor responders with respect to the Bologna criteria. Methods: All assisted reproductive technology (ART) cycles conducted from 2004 to 2018 in a tertiary center in Istanbul were analyzed retrospectively. Patients were grouped into three accordingly the count of total retrieved oocytes and metaphase-II [(M-II) -mature] oocytes after denudation (group 1: [less than or equal to] 3 oocytes and [less than or equal to] 3 M-II oocytes; group 2: >3 oocytes and 3 oocytes and >3 M-II oocytes). A Low oocyte maturity rate was diagnosed when [less than or equal to] 50% of all harvested oocytes were in the M-II stage before the fertilization procedure. Results: During the study period 14,899 intracytoplasmic sperm injection cycles were evaluated. The study group's mean age was 32.6[+ or -]5.3. The mean counts of total and mature oocytes were 9.8[+ or -]5.9 and 7.3[+ or -]4.5, respectively. A mean count of 2.38 embryos was transferred in 10118 cycles. The group 3 patients had a considerably higher live birth ratio compared to the group 1 and 2. Conclusion: We propose oocyte maturity rate and the count of M-II oocytes as two diagnostic criteria for the case definition of asynchronous follicle growth. Based on our findings, stimulation cycles ending with low oocyte maturity rate ([less than or equal to] 50%) and [less than or equal to] 3 M-II oocytes would be considered asynchronous follicle development. Patients with low oocyte maturity rate and asynchronous follicle development should be counseled and informed regarding potential poor prognosis of the treatment. Keywords: Oocytes, fertilization in vitro, ovarian reserve, ovarian stimulation, metaphase