Objective To systematically review the effectiveness of letrozole combined with GnRH antagonist for in vitro fertilization-embryo transfer (IVF-ET) in poor responders. Methods Such databases as VIP, CNKI, PubMed, EMbase and FMJS were electronically searched for randomized controlled trials (RCTs) or quasi-RCTs on the effectiveness of letrozole combined with GnRH antagonist for IVF-ET. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed methodological quality. Then, meta-analysis was performed using RevMan 5.0 software. Results Six studies involving 977 patients were finally included. The results of meta-analysis showed that, for IVF-ET poor responders, compared with the control group, the letrozole combined with GnRH antagonist group had less dosage of Gn (MD=–8.05, 95%CI –13.67 to –2.43, P=0.005), and lower serum E2 value on the day of HCG administration (MD= –1 026.41, 95%CI –1 949.61 to –103.20, P=0.03). However, no significant difference was found in the number of ocytes obtained (MD= –0.61, 95%CI –2.41 to –1.19, P=0.51) and clinical pregnancy rates (OR=1.03, 95%CI 0.53 to 2.02, P=0.92) between the two groups. Conclusion As for the effectiveness of impelling-ovulation treatment for IVF-ET in poor responders, letrozole combined with GnRH antagonist is similar to the control scheme in clinical outcomes, but it reduces the dosage of Gn and treatment costs of IVF-ET, which provides another clinical option for poor responders. Due to the limited quantity and quality of the included studies as well as the difference in methodology, we suggest this above conclusion could be taken as a reference for clinical analysis which needs to be further evaluated in its effects.
Objective To evaluate the effectiveness of GnRH antagonist on vitro fertilization-embryo transfer (IVF-ET). Methods We searched CBMdisc (1979 to 2010), Wanfang (1994 to 2010), CNKI (1994 to 2010), VIP (1989 to 2010), PubMed (1997 to 2010), PML (1997 to 2010), FMJS (2000-2010), and 9 related journals to identify randomized controlled trials (RCTs) on the comparison between GnRH antagonist (GnRHA) and GnRH agonist (GnRHa). The quality of included trials was critically appraised. RevMan 4.2.7 software was used for statistical analysis. Results Six published RCTs involving 1 208 participants were included. Compared with the GnRHa group, stimulation duration in the GnRHA group was lower (WMD= –1.07, 95%CI –1.38 to –0.76), dose of gonadotrophins (Gns) in the GnRHA group was slightly lower (WMD= –0.49, 95%CI –1.63 to 0.66), endometrial thickness at the time of HCG administration was no significant difference in the two groups (WMD= –0.09, 95%CI –0.42 to 0.24), number of oocytes retrieved in the GnRHA group was lower (WMD= –1.80, 95%CI –2.48 to –1.12), OHSS rate in the GnRHA group was slightly lower (Peto OR= 0.77, 95%CI 0.35 to 1.72), pregnancy rate in the GnRHA group was slightly lower (Peto OR= 0.83, 95%CI 0.65 to 1.05), miscarraige rate as no significant difference in the two groups (Peto OR= 1.49, 95%CI 0.79 to 2.82). Conclusions Compared with GnRHa, GnRHA requires shorter stimulation duration and less Gn, less affected the pregnancy rate, and reduces the incidence of OHSS. The use of GnRHA in clinical practice is relatively flexible with good acceptability. GnRHA for the superovulation IVF-ET offers an alternative treatment. The above conclusion still needs more well-designed, multi-center, and large-scale RCTs to confirm and update.
Objective To evaluate the effectiveness of GnRH antagonist in vitro fertilization-embryo transfer (IVF-ET) in polycystic ovary syndrome (PCOS) patients.Methods Such databases as PubMed (1997 to 2010), PML (1997 to 2010), FMJS (2000 to 2010), CBMdisc (1979 to 2010), CNKI (1994 to 2010), VIP (1989 to 2010), WanFang (1994 to 2010), and duxiu scholar searcher (www.duxiu.com), and nine relevant Chinese journals were searched for retrieving the randomized controlled trails (RCTs) on the effectiveness of GnRH antagonist versus GnRH agonist for IVF-ET in PCOS Patients. The studies were screened according to the inclusive and exclusive criteria by two reviewers independently, the data was abstracted and the quality was evaluated. The RevMan 4.2.7 software was used for Meta-analyses. Results Six grade-B studies involving 699 participants were included. The results of Meta-analyses showed that, compared with the GnRH agonist, there was no significant difference in the GnRH antagonist group about the stimulation duration (WMD= –1.23, 95%CI –2.76 to –0.31), dose of gonadotrophins (Gns) (WMD= –4.87, 95%CI –14.20 to 4.46), serum E2 value on the day of HCG administration (WMD= 31.37, 95%CI –263.40 to 326), number of oocytes retrieved (WMD= 1.34, 95%CI –1.02 to 4.70), clinical pregnancy rate (OR= 1.27, 95%CI 0.77 to2.10), and miscarraige rate (Peto OR= 0.67, 95%CI 0.38 to1.18). But the OHSS rate in the GnRH antagonist group was lower with a significant difference (Peto OR= 0.35, 95%CI 0.24 to 0.50). Conclusions Compared with the GnRH agonist protocol, the GnRH antagonist protocol can obviously reduce the incidence of OHSS, but has the same effect in Gn dose, retrieving oocytes and clinical pregnancy rate. Because the GnRH antagonist can decrease the treatment duration and cost, and has better safety, so it may be an ideal choice for PCOS patients to have IVF-ET therapy. For the quality and quantity limitation, and the methodology difference of the included studies, it is suggested that the conclusion from this study should be only served as a reference of clinical analyses, and should be revaluated and updated unceasingly.