Mild/moderate versus full stimulation.

Mild stimulation (MS) consists in prescribing gonadotropin at the minimum amount alone or in combination with other compounds. This strategy has gained popularity in assisted reproduction for the reduced costs, better patient compliance, and reduced risk of hyperstimulation syndrome. Some investigators proposed MS even in women with low prognosis. The Poseidon group proposed new criteria to identify these patients categorizing them into 4 different groups, each one characterized by a specific segment of prognosis. The use of MS in women with low prognosis involves risks that cannot be overlooked. The most crucial concerns are the increased rate of cycle cancellation and the reduced number of eggs collected. Notably, the number of eggs collected still represents the most accurate predictor of live birth and cumulative live birth rate. Despite promising preliminary data, recent evidence has confirmed that MS does not improve gamete quality. Hence, considering that no robust strategy was identified so far to improve oocyte quality, the only reasonable strategy to improve the chance of live birth in women with low prognosis is to collect the necessary number of oocytes to maximize the probability to obtain at least 1 good-quality embryo. In this sense, conventional protocols offer better results when compared with the mild approach. Given the difficulty in collecting enough oocytes in a single round of stimulation, accumulation strategy could represent a valuable approach especially in women with advanced reproductive age and reduced ovarian reserve.