FSH: urinary and recombinant.

Infertility affects approximately 10–15% of couples. To enhance the chances of conception, assisted reproductive techniques (ART) have been improved and, in the last 5 years, thousands of babies have been delivered after IVF or ICSI procedures. To obtain an appropriate and controlled ovarian hyperstimulation (COH), clinicians have introduced many drug protocols based on GnRH agonists or antagonists for pituitary down-regulation and FSH or HMG for ovarian stimulation. Currently FSH is the most common drug used for ovulation induction. It is a glycosylated protein with a molecular weight of 28000–30000Da, normally secreted by the anterior pituitary gland. The recombinant preparations of follicle stimulation hormone (r-FSH) are characterized by a higher level of purity, reduced batch to batch variability and no risk of infection. The purpose of this review was to establish the efficacy of different trials based on the use of r-FSH and urinary FSH (u-FSH) comparing published data from randomised studies on the ovulation induction for assisted reproductive techniques. Unfortunately, we did not find any paper with sufficient power to detect a clinically significant difference in pregnancy rates, however, recent meta-analysis among homogeneous trials indicates that the use of r-FSH is to be preferred to u-FSH because more oocytes were collected in cycles with better embryo quality and with more pregnancies. Recombinant FSH has a higher cost per ampoule than urinary FSH, but also a higher effectiveness. A recent cost-effectiveness analysis on follitropin alfa compared to urinary FSH-HP, using a Markov model, confirmed other previous studies that, considering the ongoing pregnancies beyond 12 weeks gestation, r-FSH is the most effective therapy for ovulation induction in ART.