Respective efficacy of gonadotrophins should be the heart of the debate

Recombinant gonadotrophins in reproductive medicine: the gold standard of today

Since the early 1980s when gonadotrophins were first routinely used in ovarian stimulation regimens, there have been important advances in pharmaceutical product development, leading to the availability today of highly purified and consistent human gonadotrophins produced by recombinant technology, that have benefited cycle management and treatment outcomes. This 'evolution' has introduced scientifically robust and 'state of the art' processes and equipment to ensure that the product is consistent, pure and safe, and is the optimal way to reduce risk of any viral, protein, and bacterial contamination. Production of human proteins by recombinant technology has resulted in improvements in product purity, consistency and delivery as well as enabling the design of future generations of gonadotrophins (e.g. longer-acting forms and orally active mimetics).

FSH and folliculogenesis: from physiology to ovarian stimulation

FSH is a glycoprotein hormone consisting of two peptide subunits. The role of FSH in folliculogenesis is well known: to stimulate the formation of a large pre-ovulatory follicle that, because of its FSH-dependent maturation, is capable of ovulation and forming a corpus luteum in response to the mid-cycle surge of LH. FSH is widely used in ovarian stimulation for assisted reproduction techniques. Ovarian stimulation protocols combine the use of human menopausal gonadotrophin, urinary FSH or recombinant FSH with gonadotrophin-releasing hormone (GnRH) agonists or antagonists in order to increase oocyte number and to avoid premature LH surge. Recently, the availability of recombinant LH has permitted new stimulation protocols, combining recombinant FSH, recombinant LH and GnRH antagonists. Due to the limitations of the new Italian law in terms of the number of oocytes that can be fertilized, protocols with a softer ovarian stimulation are now considered, reducing risk of ovarian hyperstimulation syndrome, multiple pregnancies and emotional and physical burdens on the patients. Long-acting FSH preparations are also under clinical study. Knowledge of the stereochemical three-dimensional structure of FSH and its receptor will allow the study of new non-peptide orally administered molecules that fit the FSH receptors.