Related Experiment Video
Updated: May 27, 2026

Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization
Published on: October 24, 2025
The prevalence of genuine empty follicle syndrome
Tolga B Mesen1, Bo Yu, Kevin S Richter
1Eunice Kennedy Shriver National Institute of Child Health and Human Development, Program in Reproductive and Adult Endocrinology, Bethesda, Maryland, USA.
Objective:
To describe the prevalence of "genuine" empty follicle syndrome (EFS) and "false" EFS at assisted reproductive technology (ART).
Design:
Retrospective cohort.
Setting:
Large private fertility center.
Patient(S):
A total of 12,359 patients who underwent ART between 2004 and 2009.
Intervention(S):
None.
Main Outcome Measure(S):
The failure to recover an oocyte during oocyte retrieval at ART, with and without a detectable serum β-hCG on the day of retrieval.
Result(S):
Two cases of genuine EFS and nine cases of false EFS were identified in the cohort examined. The prevalence of genuine EFS was 0.016%, and the prevalence of false EFS was 0.072%. Only two out of 11 cases of EFS were considered genuine.
Conclusion(S):
Genuine EFS is a rare occurrence. Because this syndrome tends to recur with dismal pregnancy rates at ART, continued identification and further investigation of the syndrome are needed.
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