Triggering ovulation with 250 μg or 500 μg of r-hCG in oocyte donors treated with antagonist protocol has no effect on the number of mature oocytes retrieved: a randomized clinical trial

The aim of this study is to compare two r-hCG doses to trigger ovulation (250 mu g vs. 500 mu g of r-hCG) in an oocyte donation program. A prospective, randomized study was conducted in 118 oocyte donors. Group DI received 250 mu g and Group DII received 500 mu g of r-hCG. Both the groups were homogeneous. No significant differences were found in the total dose of gonadotropins, duration of the treatment, total number of oocytes, or Metaphase II (MII) oocytes. The pregnancy rate per embryo transfer in the corresponding recipients was similar for both the groups (58.2% for DII recipients and 56.1% for DI recipients). Mild hyperstimulation was observed in 17 donors in Group DI (29%) and in 23 donors in Group DII (39%). No cases of severe ovarian hyperstimulation syndrome (SOHSS) were observed. In conclusion, a double dose of r-hCG in oocyte donors to trigger ovulation after stimulation with r-FSH and antagonist does not translate into a higher number of MII oocytes retrieved or into higher pregnancy rates among recipients. Our results confirm that the optimal dose to induce the final oocyte maturation with r-hCG is 250 mu g, and that a higher dose does not add any benefit.