For pregnancy. Sub-analysis of patients with equal demographic and clinical features
For pregnancy. Sub-analysis of patients with equal demographic and clinical features resulted in similar pregnancy rates independent PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28298493 of whether GnRH agonist or antagonist was usedFigure 3 Linear regression analysis between patient’s age and number of oocytes in the GnRH agonist group (A) and the GnRH antagonist group (B). In GnRH antagonist protocol it was observed a positive correlation between number of oocytes and patient’s age: the luteo-follicular transition induces FSH levels above the treshold for a short-period until hormonal feedback occurs, leading to the initiation of follicular growth of a few leading follicle. After exogenous FSH administration, FSH levels arise above threshold again and will initiate several additional follicles to grow, leading to a less synchronization of the follicular cohort, and a more natural recruitment of follicles. In GnRH antagonist protocol no correlation was observed between number of follicles and patient’s age. In GnRH agonist protocol, FSH levels remain above the threshold following pituitary downregulation and FSH exogenous administration, resulting in a more synchronized follicular recruitment (Depalo et al., Gynecol Endocrinol. 2009) [45].Depalo et al. Reproductive Biology and Endocrinology 2012, 10:26 http://www.rbej.com/content/10/1/Page 6 ofTable 1 Advantages and disadvantages of GnRH agonist protocols and GnRH antagonist protocolsGnRH Agonist long Advantages A. Stable and low LH and P levels throughout the HS-173 site stimulation phaseB. Suppression of endogenous FSH levels leading to a follicular cohort of all small follilcles at the initiation of FSH stimulation resulting in a synchronized follicular development GnRH Antagonist fixed A. Immediate, reversible suppression of gonadotropin secretion which avoids effects related to the initial flare up and subsequent down regulationB. Initiation of the IVF treatment in a normal menstrual cycleC. Endogenous inter-cycle FSH rise rather than FSH suppression, thus resulting in a significant reduction in the effective dosage and shorter treatment, than with GnRHa High intercycle endogenous FSH concentrations inducing secondary follicle recruitment and leading to an asynchronous follicular development GnRH Antagonist flexible A. Reduced dose of the antagonist is neededB. The cohort of follicles have more time to develop thus leading to a higher number of follicles in mid-follicular phase GnRH agonist short and ultra-short A.The ovarian suppression is not excessiveB. The initial stimulation of the GnRH receptors and consequent secretion of endogenous gonadotropins enhance the effects of the PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25645579 exogenously administered gonadotropinsDisadvantagessA. More time counsuming and complex stimulation protocolsB. Acute stimulation of gonadotropins and steroid hormones due to the flare up effectsC. Profound hypoestrogenemia due to downregulationD. Risk of complications (OHSS) A. Increased number of oocytes collectedB. Additional pregnancy chances from cryo-preserved embryosC. Improvement in routine patient treatment scheduleLH levels remain unsuppressed during the early follicular phase and enhance E2 productionFlare up effects in midfollicular phaseClinical commentsA. More IVF cycles to be carried out in a given periodB. Starting stimulation in patient scheduled for antineoplastic treatments (oocyte cryopreservation)It makes feasible to tailor stimulation to patients’ needsA. A microdose GnRHa flare protocol is useful in poor respondersB. Several microdoses of GnRHa in.