Table 1.

The consensus statements from the HERA study. No consensus was reached regarding the number of growing follicles ≥ 10 mm that would define a hyper-response. OS, ovarian stimulation

Definitions of a hyper-response

Hyper-response is characterized by the collection of ≥ 15 oocytes

A history of a hyper-response or OHSS in a prior cycle is not required to define a hyper-responder

OHSS is not relevant for the definition of hyper-response if the number of collected oocytes is above a threshold (≥15).

Recognition of pending hyper-response during ovarian stimulation

The most important factor in defining a hyper-response during the ovarian stimulation is the number of follicles ≥ 10 mm in mean diameter

Risk factors for a hyper-response—risk factors prior to OS

I consider the serum Anti Mullerian Hormone (AMH) levels when assessing the risk for a possible hyper-response

I consider the antral follicular count (AFC) when assessing the risk for a possible hyper-response

I consider the patient’s age when assessing the risk for a possible hyper-response

I do not consider the ovarian volume when assessing the risk for a possible hyper-response

In a patient without a previous ovarian stimulation, the most important risk factor for a hyper-response is the antral follicular count (AFC).

In a patient without a previous ovarian stimulation, when AMH and AFC are discordant, with one suggesting a hyper-response and the other not, AFC is the more reliable marker

Hyper-response can occur at any age

The lowest serum AMH value that would put a woman at risk for a hyper-response is ≥2 ng/ml (14.3 pMol/L).

The lowest AFC that would put a woman at risk for a hyper-response is ≥18

A patient with a history of hyper-response in a previous stimulation cycle would be considered at high risk for another hyper-response if there was no significant change in the serum AMH levels and the AFC (±3 follicles).

Women with polycystic ovarian syndrome (PCOS) as per Rotterdam criteria are at a higher risk of hyper-response than women without PCOS with equivalent follicle counts and gonadotropin doses used to stimulate

Risk factors for a hyper-response—risk factors for hyper-response during ovarian stimulation

The lowest number of growing follicles ≥ 14 mm that would characterize a hyper-response to ovarian stimulation is ≥15 follicles

The lowest peak estradiol level that would indicate a hyper-response to ovarian stimulation is ≥3000 pg/ml (11,013 pMol/l).