The relationship between follicle-stimulating hormone dose and level and its relevance for ovulation induction with adjuvant gonadotropin-releasing hormone-agonist treatment.

OBJECTIVE

To investigate the effect of a GnRH agonist (GnRH-a) on the FSH threshold level and the relationship between the FSH dose and the FSH level of patients suffering from polycystic ovarian syndrome (PCOS).

DESIGN

The stimulation with low-dose FSH in PCOS (group 1) was compared with the subsequently performed stimulation with low-dose FSH combined with GnRH-a in another group of patients suffering from the same syndrome (group 2).

SETTING

Specialist Reproductive Endocrine Unit.

PATIENTS: Suffering from clomiphene citrate-resistant PCOS.

MAIN OUTCOME MEASURES: The FSH threshold level for ongoing follicular growth and the relationship between dose and level of FSH.

RESULTS

In 15 patients in group 1 and in 13 patients in group 2, respectively, 39 and 32 stimulation cycles were performed. Below and above threshold values of FSH of group 1 and 2 did not differ significantly. For the equation stable level of FSH (Y mIU/mL) = A X infusion rate of FSH (X IU/24 h) + basal level of FSH (B mIU/mL), the median A of group 1 was 0.027 and A of group 2 was 0.055 (significant difference).

CONCLUSIONS

In PCOS, a change of the FSH threshold level for ongoing follicular growth induced by the GnRH-a could neither be proven nor ruled out. The use of a GnRH-a resulted in larger FSH level increases per IU/24 h of FSH administered and might therefore interfere with the effect of low-dose FSH treatment.