The aim of the present study was to evaluate the dose-dependent effects of gonadotropins, either singly (Bravelle (B), Luveris (L), Menupur (M), Repronex (R), Gonal-F (G), Follism (F) and Norvarel (N)) or in combination (Menupur+Bravelle; Repronext+Bravelle; and Bravelle+Norvarel), on rates of oocyte maturation, fertilisation and early embryo development in vitro in an animal model. Bovine cumulus-oocyte complexes (COCs) were purchased commercially and cultured in TCM-199 with 10% fetal bovine serum supplemented with varying concentrations of gonadotropin (0, 5, 10, 20, 40IU or United States Pharmacopoeia (USP) mL-1) for 24 and 48h according to current IVF clinical stimulation protocols. All gonadotropins enhanced oocyte maturation in vitro in a dose-dependent manner. Individually, Gonal-F (Merck KGaA, Darmstadt, Germany), Follism (Merck Co, Whitehouse Station, NJ, USA) and Repronext (Ferring, Parsippany, NJ, USA) promoted oocyte maturation; in combination, they effectively enhanced COC expansion and increased the maturation competence of MII oocytes. However, high concentrations of gonadotropins may result in maturation arrest. Specific combinations of gonadotropins may change the rate of early embryonic development (8-16-cells) and morula-blastocyst formation. These data provide support for the responsiveness of bovine oocytes to gonadotropins in vitro and the need to consider variations in the relative concentrations and ratio of combinations (FSH/LH or human chorionic gonadotropin) for optimisation of oocyte developmental competence. The results of the present study could be applied to therapeutic clinical stimulation protocols and help improve IVF success rates.

The aim of the present study was to evaluate the effect of gonadotropins (Gn) on oocyte maturation, developmental competence and apoptosis in an animal model. Bovine cumulus-oocyte complexes (COCs) were matured for 24 h in media supplemented with varying concentrations of Bravelle (B), B + Menopur (B+M) or B + Repronex (B + R) (Ferring Pharmaceuticals, Parsiappany, NJ, USA). Then, nuclear maturation, embryo development, and apoptosis in cumulus cells and oocytes were evaluated. Low to moderate Gn concentrations (75-75 00 mIUmL(-1)) effectively improved nuclear maturation and in vitro development. Higher concentrations of Gn (75 000 mIUmL(-1)) did not have any added beneficial effects and nuclear maturation and blastocyst rates in the presence of these concentrations were comparable to control (P>0.05). Most COCs showed slight apoptosis when exposed to 75, 750 and 75 00 mIUmL(-1) Gn; however, when the concentration was increased to 75 000 mIUmL(-1), the proportion of moderately apoptotic COCs increased. In conclusion, extremely high concentrations of Gn have detrimental effects on oocyte nuclear maturation and embryo development and increase apoptosis in cumulus cells, suggesting the importance of judicious use of Gn in assisted reproductive technologies (ART).

Ferring Pharmaceuticals (US) is developing a highly purified form of urofollitropin [human follicle-stimulating hormone, hFSH, FERRING hFSH, Bravelle] for use in ovarian stimulation in fertility treatments. The highly purified human-derived follicle-stimulating hormone (HP-FSH), administered by either intramuscular (IM) or subcutaneous (SC) injection, was in phase III trials in the US and in May 2002 the product received US FDA approval for use in conjunction with human chorionic gonadotropin for infertility patients undergoing ovulation induction. The product will be marketed as Bravelle. Ferring Pharmaceuticals has also submitted a New Drug Application for additional indications for Bravelle in infertility treatment, which is currently under review by the US FDA. Bravelle is produced from the urine of menopausal women and has been shown to be as effective as Organon's recombinant FSH product, Follistam. Preclinical studies have shown that Ferring Pharmaceuticals' hFSH can be mixed in the same syringe as purified human menopausal gonadotropin (hMG) to reduce the number of daily injections required in ovarian stimulation protocols without altering the bioactivity of FSH or luteinising hormone. In addition, Ferring Pharmaceuticals' hFSH administered SC or IM showed positive results compared with SC Repronex in a randomised, open-label study in patients undergoing in vitro fertilisation.Ferring Pharmaceuticals has teamed up with the American Infertility Association and RESOLVE: the National Infertility Association to improve access to infertility treatment in the US, with the recent launch of the 'Bravelle' HEART (Helping Expand Access to Reproductive Therapy) Programme. The programme is intended to provide urofollitropin treatment at significant cost savings to patients and their physicians. Serono is also developing a highly purified urofollitropin product.