Cetrorelix in an oral contraceptive-pretreated stimulation cycle compared with buserelin in IVF/ICSI patients treated with r-hFSH: a randomized, multicentre, phase IIIb study

BACKGROUND: The aim of this study was to assess the non-inferiorityof an oral contraceptive (OC)-pretreated cetrorelix regimenand a buserelin regimen in IVF/ICSI patients treated with r-hFSHin terms of total number of oocytes retrieved. METHODS: Multicentre,randomized study. One hundred and eighty two patients were randomizedto receive cetrorelix with OC pretreatment (n = 91) or to receivebuserelin (n = 91). The cetrorelix group started with dailyOCs on cycle day 5 and continued for 21–28 days. Cetrorelix(0.25 mg) was given daily from stimulation day 6 up to and includingthe day of r-hCG administration. The buserelin group startedwith buserelin (500 µg/day) for at least 10 days untildown-regulation was achieved, after which the dose was reducedto daily 200 µg up to and including the day of r-hCG administration.r-hFSH was started in both groups on a Friday, in the cetrorelixgroup 5 days after the last OC pill intake. Both regimens werefollowed by a standard IVF or ICSI procedure. The primary efficacyendpoint was the number of oocytes retrieved per patient. RESULTS:Number of oocytes, cancellation rates, r-hFSH requirements,number of oocyte retrievals during the weekend or public holidayand number of pregnancies were similar in both groups. Bothtreatment regimens were well tolerated. CONCLUSIONS: Cetrorelixpretreated with OCs resulted in similar number of oocytes retrievedcompared with a long buserelin protocol. Both regimens werewell tolerated and allowed scheduling of the oocyte retrieval,with only small number of retrievals falling on a weekend orpublic holiday.