Persistent elevation of serum oestradiol levels by functional ovarian cysts despite effective pituitary desensitization with GnRH agonists

Summary OBJECTIVE This study assessed whether functional ovarian cysts may prevent suppression of serum oestradiol levels even after pituitary desensitization had been achieved with buserelin. PATIENTS OI 288 in-vitro fertilization (IVF) cycles studied 10 patients were found to have cysts with serum oestradiol levels > 200 pmol/l despite 3 weeks of buserelin. DESIGN AND MEASUREMENTS The 10 patients with cysts were given 01 mg GnRH and serum gonadotrophins were measured at time 0, 30 and 60 minutes subsequently. Immediately following the GnRH stimulation test the cysts were aspirated transvaginally under ultrasound guidance. Serum oestradiol levels were again measured 3 days after cyst aspiration. RESULTS Basal LH and FSH levels were < 3 U/I and there was no significant rise in response to GnRH. On the day of cyst aspiration serum oestradiol levels varied between 244 and 1127 pmol/l, and in all cases serum oestradiol levels fell to < 200 pmol/l within 3 days of cyst aspiration. CONCLUSION In the presence of a functional ovarian cyst, failure to suppress the serum oestradiol level does not necessarily imply a failure of pituitary desensitization with a GnRH agonist.