Recombinant versus urinary follicle stimulating hormone for ovarian stimulation in assisted reproduction

The recent availability of recombinant follicle stimulating hormone (rFSH), with its high level of purity and batch-to-batch consistency has made it an attractive alternative to urinary FSH (uFSH) for ovarian stimulation. Several trials have compared the two preparations, but none had sufficient power to detect a clinically meaningful difference in pregnancy rates. The purpose of this study was to determine the clinical pregnancy rates per started cycle by pooling data from randomized trials which compared the use of rFSH and uFSH in treatment cycles using in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A thorough search of the literature identified 12 trials which met the inclusion criteria. In four trials, both IVF and ICSI were performed, in seven trials only IVF was performed and in one trial only ICSI was performed. Data were extracted and pooled using the principles of meta-analysis. There was no significant heterogeneity of treatment effect across the trials. The common odds ratio and the risk difference (and their 95% confidence intervals), obtained by pooling the data using a fixed effects model, were 1.20 (1.02-1.42) and 3.7% (0.5-6.9%) respectively, in favour of rFSH. The pregnancy rate with the alpha preparation of rFSH was statistically significantly higher than with uFSH in IVF cycles. The overall conclusion from this meta-analysis is that the use of rFSH in assisted reproduction is preferred over uFSH.