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

Abstract

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 İstanbul 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: ≤3 oocytes and ≤3 M-II oocytes; group 2: >3 oocytes and ≤3 M-II oocytes; group 3: >3 oocytes and >3 M-II oocytes). A Low oocyte maturity rate was diagnosed when ≤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±5.3. The mean counts of total and mature oocytes were 9.8±5.9 and 7.3±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 (≤50%) and ≤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