Comparison of recombinant human luteinising hormone (r-hLH) and human menopausal gonadotropin (hMG) in assisted reproductive technology.

Follicle-stimulating hormone (FSH) and luteinising hormone (LH) act in concert in the stimulation of folliculogenesis and ovulation. However, high levels of LH promote follicular atresia and early miscarriage, and this has led to the concept of a 'therapeutic window' of LH for successful conception in assisted reproductive technology (ART) and ovulation induction. Until now, urinary-derived human menopausal gonadotropin (hMG) has been the only available source of exogenous LH activity. hMG preparations contain highly variable levels of LH, and are often augmented with human chorionic gonadotropin (hCG), which mimics LH activity. Accumulation of hCG bioactivity, however, may have detrimental effects on follicular development and oocyte quality. Recombinant human LH (r-hLH) (Luveris) is the only pure source of LH activity. r-hLH is well characterised and production is tightly controlled, resulting in a highly consistent product. Clinical studies in hypogonadotropic hypogonadal women have demonstrated the efficacy of r-hLH, 75 IU/day, together with r-hFSH, 150 IU/day, in promoting optimal follicular development, oestrogen secretion and endometrial thickness. r-hLH therefore provides the clinician with the opportunity for precise and consistent dosing within the therapeutic window for patients requiring exogenous LH, without the risk of LH overexposure that is associated with hCG.