Authors: S. Ward RN, J.A. Parker RNC

The purpose of this study was to determine whether by reducing the amount of pituitary suppression in women 38 years of age and older, one can effectively increase the oocyte yield.

The down regulation regimen was to reduce the amount of GNRH agonist administered from 0.1 mg to 0.05 mg by diluting it half and half with sterile H2O. We then followed our regular routine for down regulation which calls for beginning gonadotropin stimulation when estradiol (E2) levels are less than or equal to 200 pmol/l.

This study was to a prospective, non randomized cohort of 12 cycles who had previously undergone a cycle using a full dose of suppression with the agonist and had been identified as prior poor responders over the age of 38.

We looked at the following parameters; age, number of ampoules of gonadtropin, number of oocytes retrieved, number of embryos, day hCG and E2 at time of hCG.

Of the 12 cycles that were initiated with the half dose suppression, the mean age was 41, the mean number of ampoules of gonadotropins used was 45.0, the mean number of oocytes collected was 5.3, the mean number of embryos was 1.5.

When we compared the identical parameters in those cycles that with the full dose suppression, the results of which indicated there was no difference in any of the above parameters.

This study demonstrates that the half dose suppression does not significantly alter the number of oocytes available for retrieval in this age group.