Abstract
Gonadotropin treatment has been used in fertility treatment since the 1930s. First, preparations coming from animals were injected, then, gonadotropins prepared from the pituitary glands of human cadavers. A great step was achieved with the introduction of human menopausal gonadotropin extracted from the urine of postmenopausal women. When cases of Creutzfeld-Jacob disease were recognized after the use of human pituitary-derived hormone injections, urinary gonadotropins were increasingly purified and then produced by the use of recombinant DNA technology. Recombinant gonadotropins were characterized by the extreme high specificity and the nearly 100% purity. This allows for follitropin alfa, the first recombinant-human follicle stimulating hormone (r-hFSH) approved, to be quantified and filled by mass, with a small variance of only ±2% and no more with a bioassay with a variance of 45%. With recombinant preparations, it is also possible to cover the tremendous growing demand for gonadotropins. Ovarian stimulation has become a self-injecting procedure for the patients. Accurate and easy-to-use injection devices which minimize pain, difficulty, and stress are essential for patient compliance. So, two pen injectors adapted from the well-known insulin pen were introduced in fertility treatment, one as a multiple-use device rechargeable with premixed, prefilled cartridges with r-hFSH (follitropin β) and the other a disposable, prefilled drug delivery system with a liquid formulation of follitropin alfa filled by mass. The efficacy in comparison to the quite more cumbersome handling with ampoules and syringes has been proven very quickly. In several studies, it has been shown that patients had a preference to the prefilled follitropin alfa pen due to the faster preparation and were more confident of accurate dosing. The follitropin alfa (filled by mass [FbM]) prefilled pen is a move toward better quality of treatment and also better quality of life for the women within the stressful period of fertility treatment.