Mild ovarian stimulation for IVF: 10 years later.

Ovarian stimulation to achieve multiple follicle development has been an integral part of IVF treatment. In the context of improved laboratory performance, the need for a large number of oocytes as an integral part of a successful IVF programme may be questioned. The aim of the current debate is to summarize the studies performed during the last decade to develop the concept of mild stimulation aiming to obtain fewer than eight oocytes. Here we examine the balance between IVF success and patient discomfort, and complications and cost, and how these might improve by simpler ovarian stimulation protocols aimed at retrieving fewer oocytes. We intend to analyse why progress has been rather slow and why there is much resistance to mild stimulation. Finally, presumed useful directions for future research will be discussed.