Ovarian hyperstimulation syndrome prevention strategies: in vitro maturation.

The only reliable way to eliminate the risk of ovarian hyperstimulation syndrome (OHSS) is complete avoidance of gonadotropin ovarian stimulation. It could be argued that in vitro maturation (IVM) of oocytes represents the most effective strategy to prevent OHSS. IVM has been an established treatment option in many centers worldwide for over a decade. The use of IVM and natural cycle in vitro fertilization (IVF) combined with IVM can result in clinical pregnancy rates that compare to those obtained with conventional IVF. The obstetric and perinatal outcomes of IVM pregnancies are similar to those conceived from stimulated IVF or spontaneous conceptions. To date, more than a thousand healthy infants have been born without an increase in fetal abnormalities. Although IVM may not replace standard IVF, it plays an increasingly important role in assisted reproductive technology, especially in the settings of high responders and those patients at risk of OHSS.