Women requiring larger doses of stimulation drugs are commonly called "poor responders". Although there is no clear definition for what can be considered a low response to IVF drugs, many authors use a cut-off of less than 4 mature eggs at the time of hCG shots or an estradiol level of less than 500.
Low response is detected through ovarian reserve testing, including basal FSH levels. Ultrasound assessment of the ovaries and the antral follicle number are also good predictors of poor responders to stimulation drugs.
A cycle can be cancelled if less than 4 mature eggs are produced or if no response is obtained at all.