Background: The potentially detrimental role of progesterone during the follicular phase has been a matter of controversy for several years; however, few studies have analyzed the effects of combined raised estradiol and progesterone levels on pregnancy outcomes. The aim of the present study was to determine the influence of high progesterone levels on clinical outcomes in the context of high ovarian response.
Methods: We performed a retrospective cohort study that included 2850 women classified as high responders. The women were subdivided into six groups depending on their progesterone concentration on the day of human chorionic gonadotropin (hCG) administration: <0.5 ng/ml (<p10), 0.50-0.70 ng/ml (p10-p25), 0.71-1.00 ng/ml (p25-p50), 1.01-1.40 ng/ml (p50-p75), 1.41-1.80 ng/ml (p75-p90) and >1.81 ng/ml (>p90). Ovarian response was classified as high when>=20 oocytes were retrieved or when estradiol was >=3000 pg/ml. Clinical outcomes of each subgroup were analyzed. We also examined data from frozen-thawed embryo transfers. Results were analyzed with Student's t- test to compare continuous variables and chi-squared test to compare proportions. A p-value of< =0.05 was considered statistically significant.
Results: The progesterone concentration increased with ovarian response, and elevated progesterone did not show a significant clinical impact on implantation rate and pregnancy rates. These data provide evidence that progesterone levels higher than 1.8 ng/ml do not have detrimental effect on oocyte quality or endometrial receptivity.
Conclusions: These data allow us to conclude that high progesterone levels correlate significantly with high estradiol levels and that in high responder women; progesterone levels do not show a significant clinical impact on results.