Administration of GnRH antagonists in case of elevated progesterone at initiation of the cycle: a prospective cohort study

In patients with elevated progesterone levels at the beginning of an ART (assisted reproductive technology) treatment cycle, the outcome of controlled ovarian stimulation (COS) may be inappropriate. A prospective cohort study was conducted to investigate whether the administration of a GnRH antagonist prior to the start of COS in these patients could lead to a similar pregnancy rate than in case of normal progesterone. Four hundred eighty-four patients were included in this study between February 2009 and July 2009. COS was initiated on day 2 of the cycle when estradiol (E(2)) and progesterone (P) serum levels were normal (E(2) ≤ 80 pg/ml, P ≤ 1.5 ng/ml; 'normal P group'). When serum progesterone was > 1.5 ng/ml on day 2 of the cycle ('high P group'), stimulation was not initiated, instead a GnRH antagonist was administered at a dosage of 0.25 mg during three consecutive days. In both study groups, efficient ovarian stimulation ensued and pregnancy rates did not diverge significantly. The results of the study led us to conclude that administration of a GnRH antagonist normalizes progesterone levels in those cases with isolated elevated serum progesterone levels at the start of the ART treatment cycle, and that this pretreatment is compatible with adequate ovarian stimulation and results in acceptable pregnancy rates.