Utilization of the Bologna criteria: a promise unfulfilled? A review of published and unpublished/ongoing trials.

Objective: To study the use of the Bologna criteria (BC) for the definition of poor ovarian responders (POR) in clinical practice and research.

Design: Systematic review of published and unpublished/ongoing trials between January 2012 and August 2017 on POR.

Setting: Not applicable.

Patient(s): Not applicable.

Intervention(s): The databases were searched using the relevant medical subject headings including all subheadings. The search was limited to humans and English language. The references of the included studies were cross-searched for possibly missed articles. Only clinical trials providing an evidence level ≥ III were included. Case reports, review, letters, and hypothetical articles were excluded.

Main Outcome Measure(s): Extracted studies were divided into two groups: studies in which the BC were used or not.

Result(s): One hundred nine published clinical studies analyzing a total of 30,540 women and 112 unpublished/ongoing trials were identified. The BC were used to define POR in 56 (51%) of the published and 44 (39%) of the unpublished trials. The use of the BC gradually increased from 29% to 53% from 2012 to 2017. Asian researchers were more likely to use the BC compared with European and North American researchers (65%, 49%, and 23%, respectively). Neither the design of the study nor the impact factor of the publishing journal was correlated with the use of the BC.

Conclusion(s): There is still reluctance to use the BC for the definition of POR, which makes it difficult to combine data from small studies and reach a meaningful conclusion.