Optimizing the gonadotrophin dose regimen.

ABSTRACT

The starting dose of gonadotrophin for controlled ovarian stimulation (COS) or ovulation induction (OI) must be individualized and has considerable impact on outcomes (pregnancy and adverse events). Five large randomized, controlled trials have compared fixed doses of recombinant follicle-stimulating hormone (rFSH) for COS for assisted reproductive technology (ART). Among young women, a fixed dosage of 200 IU/day (versus 100 IU/day) yielded more oocytes and more transferable embryos. Thus, if surplus embryos can be cryopreserved, it could result in a higher cumulative pregnancy rate. However, no clear dose-response relationship was evident among older women receiving either 150 or 250 IU/day. Another randomized, controlled trial showed that a low-dose step-up OI protocol with weekly increments of 25 IU/day of rFSH was more effective and more efficient than a regimen with 50-IU/day increments. Research to develop a normogram for the optimal starting dose of rFSH for individual patients is under way.