Significant reduction of the incidence of ovarian hyperstimulation syndrome (OHSS) by using the LHRH antagonist Cetrorelix (Cetrotide (R)) in controlled ovarian stimulation for assisted reproduction

A prospective, randomized study was per formed to compare the efficiency of hormonal stimulation for IVF (in vitro fertilization) in either the long l uteal protocol, using the LHRH agonist Buserelin, or the multiple dose LHRH antagonist protocol, using the LHRH antagonist Cetrorelix. Here we present the data on the incidence of ovarian hyperstimulation syndromes (OHSS). 85 and 188 patients were recruited for the stimulation in the LHRH agonist an d in the LHRH antagonist protocol, respectively. The groups were comparable regarding anamnestic data. The incidence of WHO degrees II and degrees III OHSS was significantly lower in the Cetrorelix than in the Buserelin group (1.1% vs. 6.5%, p=0.03). Additionally 3 patients in the Cetrorelix group ( 1.6%) and 5 patients in the Buserelin group (5.9%) did not receive hCG beca use of a threatening OHSS. The follicle maturation was more homogeneous in the Cetrorelix protocol, with less small follicles on the day of hCG admini stration but a similar number of oocyte cumulus complexes retrieved. The pr egnancy rates per cycle were not significantly different in the Cetrorelix and Buserelin protocol (22% vs. 26%). The Cetrorelix multiple dose protocol is advantageous compared to the long protocol regarding the incidence of O HSS, a potentially life threatening complication of controlled ovarian stim ulation.