UTILIZATION OF RETRIEVED OOCYTES AS AN INDEX OF THE EFFICIENCY OF SUPEROVULATION STRATEGIES FOR IN-VITRO FERTILIZATION TREATMENT

An analysis of 581 in-vitro fertilization treatment cycles was carried out to determine the pattern of utilization of retrieved oocytes. Pat ients were divided into five groups depending on the number of retriev ed oocytes. The mean fertilization rate of 57% was broadly similar amo ngst the groups but the proportion of retrieved oocytes that produced embryos of a quality suitable for transfer or cryopreservation (the cy cle efficiency index) fell significantly with increase in the retrieve d oocyte number. However, the pregnancy rate increased with the number of retrieved oocytes (13-38%). It is important to determine the point at which advantages of multifollicular development are outweighed by the potential for complications. Increased utilization of retrieved oo cytes will decrease the need for production of a large number of oocyt es.