Nist protocols include less flexible options in terms of cycle programming
Nist protocols include less flexible options in terms of cycle programming and early studies suggesting a minor reduction in pregnancy rates per cycle [20,21]. Increasing flexibility of GnRH antagonist protocols can be achieved with oral contraceptives [20]. Pretreatment with oral contraceptives allows programming of cycles, whereby stimulation can be started during a 5-day interval following withdrawal of the oral contraceptive [22]. Use of oral contraceptives with a GnRH antagonist protocol and the pregnancy outcomes of GnRH antagonist protocols are discussed below.Pregnancy outcomes of GnRH antagonist protocolsDespite an initial trend toward a lower pregnancy rate with GnRH antagonists compared with agonists in a number of early randomized controlled studies, a metaanalysis by Kolibianakis et al. [23] and a review PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28499442 by TurKaspa and Ezcurra [24] found no significant difference in the probability of live birth rates with the use of either a GnRH agonist or antagonist protocol [23] (Table 1). In normal responders, the use of GnRH antagonist versus long GnRH agonist protocols was associated with a statistically significant reduction of OHSS, with no evidence of a difference in live birth rates [45]. GnRH antagonist protocols have been shown to result in better outcomes than GnRH agonists in patients with poor prognosis [52,53]. In a meta-analysis of six clinical trials comparing GnRH antagonist versus GnRH agonist protocols PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25432023 in poor ovarian responders in IVF/intracytoplasmic sperm injection (ICSI) cycles Franco et al. [54] indicated no difference between GnRH antagonists and agonists with respect to cycle cancellation rate, number of mature oocytes, and clinical pregnancy rate per cycle initiated, per oocyte retrieval, and per embryo transfer. Al-Inany et al.Figure 1 Schematic presentation of the ganirelix treatment regimen.Copperman and Benadiva Reproductive Biology and Endocrinology 2013, 11:20 http://www.rbej.com/content/11/1/Page 3 ofTable 1 Results of meta-analyses of GnRH analogs among patients treated for IVF ?odds ratio of live birth rateGnRH antagonists Events RCTs included in Kolibianakis et al. [23] Albano 2001 [25] European 2000 [8] Olivennes 2000 [26] N American 2001 [27] Middle East 2001 [28] Akman 2001 [29] Hohmann 2003 [30] Martinez 2003 [31] Franco 2003 [32] Hwang 2004 [33] Sauer 2004 [34] Loutradis 2004 [35] Check 2004 [36] Xavier 2005 [37] Malmusi 2005 [38] Marci 2005 [39] Cheung 2005 [40] Barmat 2005 [41] Bahceci 2005 [42] Badrawi 2005 [15] Schmidt 2005 [43] Lee 2005 [44] Total (n = 22) RCTs included in Al-Inany et al. [45] All women Albano 2000 [25] Barmat 2005 [41] Heijnen 2007 [46] Hurine 2006 [47] Kim 2009 [48] Kurzawa 2008 [49] Lin 2006 [50] Marci 2005 [39] Ye 2009 [51] Subtotal (95 CI) Total events Heijnen 2007 [46] Lin 2006 [50] Subtotal (95 CI) Total events Heterogeneity: 2 = 0.32, df = 1 (P = 0.57) Test for Chloroquine (diphosphate) custom synthesis overall effect: Z = 0.66 (P = 0.51) 97 222 70 22 205 60 265 102 34 13 70 17 13 14 22 4 35 198 40 205 91 54 37 60 30 109 824 217 78 21 199 60 259 79.7 8.4 100.0 0.80 (0.54?.21) 1.08 (0.51?.27) 0.89 (0.62?.26) 19 17 78 17 8 18 21 0 39 95 40 199 91 28 37 60 30 111 691 13.5 7.3 33.0 8.8 5.1 7.1 8.4 0.3 16.6 100.0 0.83 (0.44?.55) 0.65 (0.26?.62) 0.80 (0.54?.21) 1.00 (0.47?.11) 0.79 (0.28?.22) 0.64 (0.25?.62) 1.08 (0.51?.27) 10.36 (0.53?01.45) 0.87 (0.50?.53) 0.86 (0.69?.08) 34 97 22 60 72 4 18 4 3 8 9 9 8 7 5 4 3 13 29 11 3 13 436 198 486 126 208 236 24 111 21 14 27 24 58 30 66 30 30 33 40 73 50 24.