Granulosa Cell Aromatase Activity in Women Undergoing IVF: A Comparison of Good and Poor Responders

OBJECTIVE: We wished to investigate the aromatase activity (AA) of granulosa cells (GCs) in women undergoing ovarian follicular stimulation for in vitro fertilization (IVF). METHODS: Granulosa cells were harvested from follicular fluid aspirated at the time of oocyte retrieval in women undergoing IVF. Data related to the follicular stimulation and IVF were collected by chart review. We conducted a retrospective analysis of the relation between the response to stimulation and the AA of GCs obtained from IVF patients. We assessed the response to stimulation by calculation of the area under the curve (AUC) of the monitored serum estradiol levels, and divided patients into "poor responders" and "good responders." RESULTS: There was no difference in AA between women with a poor response to stimulation and women with a good response. Implantation rates and pregnancy rates were significantly lower in poor responders (5.3% and 9.1% respectively) than in good responders (19.7% and 54.8% respectively), even though embryo quality was similar in each group. CONCLUSIONS: Women who have a poor response to ovarian follicular stimulation preceding IVF have lower pregnancy rates than women with a good response. The lower pregnancy rates do not appear to be a consequence of an abnormal follicular environment, because AA and the ratio of serum estradiol AUC to oocytes retrieved was similar in both groups of women.