Empty follicle syndrome is an uncommon situation in which no eggs are obtained at egg retrieval despite follicles developing to an apparently normal size on ultrasound and hormone levels appearing consistent with a good response to stimulation. It is sometimes linked to issues with trigger timing or absorption, though in some cases no clear cause is identified. Because this is uncommon and its causes are not fully understood, the treating fertility team reviews the details of the stimulation and trigger used, and discusses options for a future cycle, which may include a change in trigger approach or protocol. It is a recognised, though rare, event and is not something that could have been foreseen from monitoring alone in every case.
Also known as: EFS
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.