Simultaneous evaluation of basal FSH and oestradiol response to GnRH analogue (F-G-test) allows effective drug regimen selection for IVF.

To determine whether preliminary assessment of ovarian reserve by simultaneous evaluation of basal follicle-stimulating hormone (FSH) and oestradiol response to gonadotrophin releasing hormone (GnRH) analogue (F-G-test) can be used to tailor individually the drug regimen for ovarian stimulation, the in-vitro fertilization (IVF) results of 238 patients were retrospectively analysed. Sixty-two women with abnormal response to the test (DeltaE2 <180 pmol/l and/or FSH >9.5 mIU/ml) had commenced buserelin nasal spray in the mid-luteal phase and discontinued it on cycle day 1. Ovarian stimulation was started on cycle day 3 with 375 IU/day of gonadotrophin. Fifty-three patients completed the treatment cycle (group A). A total of 176 women with normal response to the test (DeltaE2 >180 pmol/l and FSH <9.5 mIU/ml) had continued the GnRH analogue throughout the stimulation cycle and a starting dose of 225 IU/day of gonadotrophin was used from cycle day 3. A total of 158 patients completed the treatment cycle (group B). Group A had significantly higher age (34.9 +/- 4.2 versus 33.2 +/- 4.2) (P < 0.05) and basal FSH (9.2 +/- 3.8 versus 7.0 +/- 2.2) (P < 0.05) and required a higher total dose of gonadotrophin. The numbers of oocytes retrieved and embryos transferred were significantly lower. However, fertilization, clinical pregnancies, and implantation rates were similar in both groups. It was concluded that simultaneous evaluation of basal FSH and oestradiol response to GnRH analogue can be useful in identifying subcategories of women with reduced ovarian reserve who may benefit from reduced GnRH analogue administration and a higher starting dose of gonadotrophin.