Introduction: The hypothalomo-pituitary response to the loss of ovarian function due to ageing is an increase in GnRH induced gonadothropic activity: FSH. It is thought that the pituitary gives maximum endogenous stimulation leading to FSH levels above the ovarian threshold to develop follicular growth and it is a matter of debate whether exogenous FSH (r-FSH) will or will not improve ovarian response. In intrauterine insemination (IUI) treatment r-FSH is used to induce multifollicular growth to improve treatment efficacy. This study evaluated whether addition of r-FSH in women with endogenous elevated basal FSH levels, results in a higher percentage of cycles with multifollicular growth.
Methods: A randomized controlled trial was performed in women undergoing IUI treatment with elevated basal FSH levels (≥10 IU/l on cycle day 3). Patients were assigned to the control (3 natural cycles followed by 3 stimulated cycles) or the intervention group (6 stimulated cycles). The primary outcome was the occurrence of multifollicular growth. Statistical analysis was done using Cox regression and multivariate analysis.
Results: Fourty-eight women were included; 23 in the control versus 25 in the intervention group. There were no significant differences in baseline characteristics. The intervention group was 2.7 times more likely to develop multiple follicular growth (95% CI, 1.166.11, P=0.02). Lower FSH levels at the beginning of a treatment cycle compared to basal FSH levels predicted multifollicular growth with an odds ratio of 0.81 (95% CI, 0.720.92, P=0.0003).
Conclusion: Administration of r-FSH in women with elevated basal FSH levels undergoing IUI treatment leads to a higher percentage of cycles showing multifollicular growth. A lower FSH level in the beginning of the treatment cycle compared to basal FSH levels predicts multifollicular growth. Therefore, women with elevated basal FSH levels should be offered controlled ovarian stimulation in order to improve treatment outcome.
30 Apr - 04 May 2011
European Society of Endocrinology