SERUM FSH-LEVELS IN WOMEN WITH POLYCYSTIC-OVARY-SYNDROME DURING OVULATION INDUCTION USING DOWN-REGULATION AND UROFOLLITROPIN

Objective: To evaluate retrospectively the use of serum FSH levels and to correlate them with follicular growth in a clinical ovulation indu ction program. Methods: Twenty women with infertility due to anovulati on associated with polycystic ovary syndrome (PCOS) were studied. The patients were down-regulated with a long GnRH agonist protocol and sti mulated with purified urofollitropin, using a low-dose step-up regimen , Repeated serum samples were drawn and transvaginal ultrasound scans were performed. During the exogenous FSH therapy serum FSH levels resu lting in continuous follicular growth were analyzed, as well as the ra tes of ovulation, pregnancy, cancellation and conversion to in vitro f ertilization (TVF). Results: Thirty-two out of fifty treatment cycles led to ovulation, resulting in five term pregnancies. Eight cycles wer e converted to IVF/embryo transfer due to multiple follicular growth. They resulted in two pregnancies. Ten cycles were cancelled because of impaired follicular growth. The serum FSH levels (median 6 IU/l) resu lting in continuous growth of the follicles were relatively stable wit hin patients (variation 15%) but varied considerably between patients (45%), The relationship between FSH dose and serum level was different for lean and obese PCOS patients after subcutaneously injected urofol litropin. Conclusions: There seems to be a difference in resorption/me tabolism between lean and obese PCOS patients with regard to s.c. inje cted FSH. The intra-patient coefficient of variation (C.V.) of the ser um FSH response level was quite low as was the C.V. of the FSH dose at the response level. This allowed a more rapid dose adjustment in subs equent cycles. Analysis of serum FSH during induction of ovulation wit h gonadotropins seems to be of limited value in clinical programs.