Is gonadotropin stimulation bad for oocytes?

Purpose of review Gonadotrophin in IVF increases the number of oocytes retrieved, and many doctors regard a high number of oocytes as a measurement of success in IVF. Thus, the dogma of more oocytes provides better IVF success has been broadly accepted. However, some European fertility specialists have argued against this concept, saying fewer eggs might, in some instances, be a better option for the patient. Recent findings The concept of 'one size fits all' stimulation in artificial reproductive technologies is not broadly supported by the current literature. The ovarian stimulation strategy has to be viewed in relation to cost, infrastructure and economics, expectations from the doctors and the patients, and more importantly the local legislation. Furthermore, also luteal phase, epigenetic factors and patient safety is a matter of concern. Studies show that in the fresh cycle, ovarian stimulation might have an impact on the epigenetics, quality of the embryo and increase the risk of ovarian hyper stimulation. Strategies like agonist triggering or 'freeze all' can help during a fresh cycle. However, there is an ongoing debate whether these strategies might increase time to pregnancy or not. Summary In conclusion, each fertility clinic setup has its own benefits and gonadotropin hyperstimulation in IVF has to be related to this and the specific patient demographic in the clinic; however, epigenetics and time to pregnancy are still issues open to debate.