Discussing about the ideal number of oocytes with pre-vitrification data. Gorka Barrenetxea
Many of the debates during last ESHRE meeting were focused on the ideal number of oocytes to achieve a pregnancy (or to have a reasonable chance of pregnancy). Too few oocytes meant a bad prognosis; too many a risk of ovarian hyperstimulation syndrome (OHSS). Thus, the highest chance of pregnancy was reached with 12 to 16 oocytes approximately.
But things (fortunately) have changed. First, efficient preservation methods such as vitrification (either of oocytes or embryos) allow us to achieve a pregnancy with successive frozen-thawed embryo transfers (so that one ovarian stimulation procedure gives us the opportunity of preforming more embryo transfers).
Second, thanks to the use of Gn-RH antagonists during ovarian stimulation, ovulation triggering may be performed with agonists (instead of HCG) thus reducing the risk of OHSS.
Thus, we should not use data from “old cycles” and, instead, we should take advantage of available vitrification procedures and the improvements in our labs.