The question of whether adjustment to
body weight is necessary in in-vitro fertilization (IVF) cycles using
GnRH antagonists is currently under discussion. Therefore, a data analysis of five prospective studies using either the single- or the multiple-dose antagonist protocol with
cetrorelix (
Cetrotide) was performed. The influence of stimulation procedure, gonadotrophins and
body weight on pregnancy rate was evaluated in a linear logit model. The effect of the stimulation procedure and
body weight on the cumulus-oocyte complex (COC) and follicle number was explored in an ANOVA model.
Cetrorelix plasma concentrations were tested for any correlation with
body weight. Baseline and outcome parameters in different
body weight groups (<50 kg, 50-59 kg, 60-69 kg, 70-79 kg, > or =80 kg) were assessed for human menopausal gonadotrophin and recombinant
human FSH stimulation separately.
Cetrorelix plasma concentrations were correlated with
body weight, but no influence of the type of stimulation or
body weight on pregnancy rate was found.
Body weight did not influence
cetrorelix plasma concentrations. In contrast,
body weight significantly influenced the number of retrieved COC as well as the number of follicles on the day of human chorionic gonadotrophin administration.
Body weight does not influence the outcome of treatment in
cetrorelix cycles.