Follicular waves in the human ovary

Abstract

Follicular waves can be defined as a synchronized growth of a group of antral follicles, among which one or more follicles will be selected for subsequent development and ovulation. These waves occur at regular intervals during the menstrual cycle. The synchronization of the wave beginning and the ovarian stimulation improves the outcomes of the IVF treatment. Follicular waves are a natural phenomenon, and they develop in association with increased concentration of follicle stimulating hormone levels. Studies indicate that the follicular recruitment event occurs only once during the cycle; however, recent studies suggest that the recruitment can occur more than once during the same cycle. Several studies have demonstrated groups of women with two follicular waves and others with up to three waves during the normal menstrual cycle. Follicles recruited during these waves have the potential to ovulate in the presence of an luteinizing hormone surge, providing women, especially the poor responders, a more efficient and less expensive treatment. The majority of studies agree that there is not just a single wave of follicular recruitment during a menstrual cycle and this involves the optimization of treatment of poor responders, expanding the window of action for oocyte retrieval and avoiding expensive treatments.