Oocyte maturation and its clinical significance in assisted reproductive technology

The characteristics and regulation of oocyte maturation in the normal menstrual cycle is reviewed and the mechanisms by which ovarian hyperstimulation with exogenous gonadotrophins, used in assisted reproductive techniques, can disturb this process, is discussed. It is postulated that derangements induced in the maturation of oocytes in the hyperstimulated cycle result in the recovery of poor quality oocytes at egg-pickup which have a reduced potential to undergo normal fertilisation and subsequent embryonic development.