deslorelin and Infertility

The effects of gonadotrophin-releasing hormone agonist (GnRH-a) administered in the luteal phase remains controversial. This meta-analysis aimed to evaluate the effect of the administration of a single-dose of GnRH-a in the luteal phase on ICSI clinical outcomes.. The research strategy included the online search of databases. Only randomized studies were included. The outcomes analyzed were implantation rate, clinical pregnancy rate (CPR) per transfer and ongoing pregnancy rate. The fixed effects model was used for odds ratio. In all trials, a single dose of GnRH-a was administered at day 5/6 after ICSI procedures.. All cycles presented statistically significantly higher rates of implantation (P<0.0001), CPR per transfer (P=0.006) and ongoing pregnancy (P=0.02) in the group that received luteal-phase GnRH-a administration than in the control group (without luteal-phase-GnRH-a administration). When meta-analysis was carried out only in trials that had used long GnRH-a ovarian stimulation protocol, CPR per transfer (P=0.06) and ongoing pregnancy (P=0.23) rates were not significantly different between the groups, but implantation rate was significant higher (P=0.02) in the group that received luteal-phase-GnRH-a administration. On the other hand, the results from trials that had used GnRH antagonist multi-dose ovarian stimulation protocol showed statistically significantly higher implantation (P=0.0002), CPR per transfer (P=0.04) and ongoing pregnancy rate (P=0.04) in the luteal-phase-GnRH-a administration group. The majority of the results presented heterogeneity.. These findings demonstrate that the luteal-phase single-dose GnRH-a administration can increase implantation rate in all cycles and CPR per transfer and ongoing pregnancy rate in cycles with GnRH antagonist ovarian stimulation protocol. Nevertheless, by considering the heterogeneity between the trials, it seems premature to recommend the use of GnRH-a in the luteal phase. Additional randomized controlled trials are necessary before evidence-based recommendations can be provided.

Topics: Algorithms; Dose-Response Relationship, Drug; Female; Fertility Agents, Female; Gonadotropin-Releasing Hormone; Humans; Infertility; Luteal Phase; Ovulation Induction; Pregnancy; Pregnancy Rate; Randomized Controlled Trials as Topic; Sperm Injections, Intracytoplasmic; Treatment Outcome; Triptorelin Pamoate

Objectives Gonadotropin-releasing hormone (GnRH) agonists like deslorelin are being increasingly used in tom cats for their efficacy in controlling reproductive behaviour and fertility. Deslorelin implants have been widely available in Europe since 2008. Little, if anything, is known about the interval between treatment and onset of sterility, as well as semen quality, after treatment in tom cats. The purpose of this study was to investigate semen quality and interval to sterility in tom cats treated with a 9.4 mg deslorelin implant. Methods Fifteen healthy adult tom cats were treated with a 9.4 mg deslorelin implant (Suprelorin 12). For each cat, semen collection and a GnRH stimulation test (intramuscular administration of 50 μg gonadorelin [Fertagyl], followed by blood sampling 1 h later, to assay serum testosterone) were performed on the first consultation and then repeated every 15 days until complete sterility was achieved. Semen collection was performed by introducing a 14 cm, open-end feline catheter (Argyle) 9 cm into the distal urethra 10 mins after sedation by intramuscular injection of 100 μg/kg medetomidine (Domitor). Results Semen collection was not successful in all cats at each attempt. In the first month after treatment, the semen of only four cats could be evaluated, while the semen of eight cats could be evaluated during the second and third months of the study. Semen quality (ejaculate volume, progressive motility and morphological abnormalities) improved slightly during the first 19-25 days in 2/4 cats, and in 1/4 cats motility was still very high (80%) 25 days post-treatment (PT), but we have no data regarding fertility prior to treatment in this cat. The last cat never produced spermatozoa. Subsequently, semen quality gradually worsened in all cats from 30 days onwards. At 70 days PT, one cat was still potentially fertile. After 72 days all cats were sterile. Conclusions and relevance Semen quality increased slightly in treated cats during the first month after treatment, and then gradually decreased over the following months. Complete sterility was reached within 40-72 days following implantation.

Topics: Animals; Cat Diseases; Cats; Contraception; Contraceptive Agents, Male; Drug Implants; Infertility; Infertility, Male; Male; Semen; Semen Analysis; Sexual Behavior, Animal; Triptorelin Pamoate

Over the last 40 years, researchers have explored methods to non-surgically suppress fertility in animals. Immunocontraception has been used to control wildlife populations but does not confer long-term immunity. The gonadotropin-releasing hormone (GnRH) agonist deslorelin, formulated as an implant to provide 6-month to 1-year suppression of fertility in male dogs, is available commercially in some countries. Neither of these approaches provide permanent sterility. A single-dose, permanent treatment would be a valuable tool in dog and cat population control. The Michelson Prize and Grants (MPG) programme was initiated "to eliminate shelter euthanasia of healthy, adoptable companion animals and reduce populations of feral and free-roaming cats and dogs" offering a $25 million US prize for a non-surgical sterilant that is effective as a single treatment in both male and female dogs and cats. Michelson Prize and Grants programme has offered US $50 million in grant money for research and has attracted scientists worldwide. Approaches under study include gene therapy, small interfering RNA to inhibit reproductive targets and delivery of cytotoxins to pituitary gonadotrophs or GnRH producing neurons in the hypothalamus. Research in implant technology that could deliver compounds over an animal's lifetime is also underway. Details of funded grants and results to date can be found at: http://www.michelsonprizeandgrants.org/michelson-grants/research-findings. The next steps are translating the most promising research into products. The Alliance for Contraception of Cats and Dogs (ACC&D) is helping to research practical methods of marking sterilized animals to avoid costly retreatment and population modelling that will help guide field workers in use of resources for sterilization programmes.

Topics: Animals; Awards and Prizes; Cats; Contraception; Contraception, Immunologic; Contraceptive Agents; Cytotoxins; Dogs; Drug Implants; Female; Gene Silencing; Gonadotropin-Releasing Hormone; Infertility; Male; Population Control; Research Support as Topic; RNA, Small Interfering; Sterilization, Reproductive; Triptorelin Pamoate