Estradiol and follicle-stimulating hormone levels in oophorectomized women using vaginal estrogen

To assess the changing estradiol (E2) and follicle-stimulating hormone (FSH) level in oophorectomized women using vaginal estrogen. Serum estradiol and FSH were evaluated in 32 oophorectomized women using a daily dose of 2 g base of 1.25 mg vaginal conjugated equine estrogen (CEE) cream. The blood sample for hormone assay was collected 8-10 hours from the time of vaginal application. E2 and FSH levels were measured in the serum sample before and after commencing the study at 4, 8 and 12 weeks using the time-resolved fluoroimmunoassay method. Serum estradiol significantly increased from baseline value at 4, 8 and 12 weeks. (Mean +/- SD of E2 value at 0, 4, 8, 12 weeks: 9.97 +/- 12.13, 249.83 +/- 170.46, 299.38 +/- 190.65, 322.82 +/- 218.31 pmol/L, respectively, P < 0.05) On the other hand, serum FSH significantly decreased from baseline value at 4, 8 and 12 weeks. (Mean +/- SD of FSH value at 0, 4, 8, 12 weeks: 77.64 +/- 27.24, 40.33 +/- 21.64, 38.84 +/- 22.33, 30.90 +/- 24.32 IU/L, respectively, P < 0.05) In conclusion, a daily dose of 2 g vaginal CEE cream raised the serum estradiol level close to the normal level in the follicular phase of the normal menstrual cycle. However, even though FSH significantly decreased it did not reach the premenopausal level.