The Impact Of Two Doses Of GnRH Antagonist (Cetrorelix) On The Outcome Of IVF/ICSI-ET

Objective: Gonadotrophin-releasing hormone antagonists （GnRHant）can be used to prevent luteinizing hormone （LH） surges during controlledovarian stimulation （COS） with a dose-dependence effect. In this study, wecompared the clinical effects and results of regimens with different dose ofcetrorelix in order to find out the lowest effective dose in the in vitrofertilization and embryo transfer/intracyto-plasmic sperm injection（IVF/ICSI-ET）.Methods: A retrospective analysis was conducted in patients undergoingGnRH antagonist protocols in our IVF unit from June2010to December2011.470cases without polycystic ovary syndrome （PCOS） were analysed andcategorized into three groups according to the dose of cetrorelix: In group A,patients were not initiated any cetrorelix. In group B, ovarian stimulationincluded cetrorelix0.125mg daily during late follicular phase administration.In group C, the dose of cetrorelix was increased to0.25mg daily. Descriptivestatistics were recorded for the patients’ age, body mass index （BMI）,infertilityduration, antral follicular count, number of IVF attempts, basal FSH level,basal LH level, basal E2level, T level, PRL level, rate of infertility factorsamong the three groups, number of days of stimulation on the day of GnRHantinjection and number of days of GnRH antagonist treatment,consumption ofGnRH antagonist, serum LH level and diameter of follicles on the day ofantagonist use, number of days of stimulation, the total gonadotropin doseadministered, serum hormone （LH, E₂, P） level and endometrial thickness onthe day of hCG administration, number of oocytes collected, fertilization rate,cleavage rate, No. of viable embryos，rate of viable embryos, implantation rate,pregnancy rate, cycle cancellation rate and all embryos cryopreservation rate,embryo cryopreservation rate. Result: A total of48cycles were included in group A,227in group Band195in group C. There were no statistical significant differences amongthe three study groups with respect to the mean age, BMI, infertility duration,number of IVF attempts, basal FSH level, basal LH level, basal E2level, Tlevel, PRL level, rate of infertility factors（P＞0.05）. Antral follicular count ofgroup A （5.7±3.2） was significantly different from group B（7.6±4.3）and groupC（7.5±3.4）（P＜0.05）. Antral follicular count of group B was similar to thatof group C（P＞0.05）.Between group B and group C, comparable results wereobserved in terms of the number of days of stimulation on the day of GnRHantinjection （COS day7.4±1.5vs day7.4±1.6）, number of days of GnRHantagonist treatment （2.8±1.2days vs2.9±1.4days） of GnRH antagonisttreatment, and also the diameter of follicles （14.4±2.0mm vs14.4±1.8mm） onthe day of GnRH antagonist use（P＞0.05）. The consumption of cetrorelix ofgroup B （1.4±0.6ampouls） was much less than that of group C（2.9±1.4ampouls）（P＜0.05）, and serum LH level on the day of cetrorelix use of groupB（4.7±2.6mIU/ml） was lower than that of group C（7.3±4.2mIU/ml）（P＜0.05）. No significant differences were recorded for the total gonadotropin doseadministered, number of days of stimulation, serum P level and endometrialthickness on the day of hCG administration among the three groups（P＞0.05）.There was highest LH level on the day of HCG injection in group A（5.2±5.6mIU/ml） in comparison to the other two groups（P＜0.05）, and that in group Band group C were equal to each other（P＞0.05）. Rate of LH＞10mIU/mL onthe day of HCG injection in group A was16.67%,2.64%in group B, and3.08%in group C.That in group A was significantly highest （P＜0.001）,andthat in group B was comparable to that in group C（P=1.000）. The E2level onthe day when maturation was triggered was1586.6±1267.5pg/ml in group A,2330.3±1407.2pg/ml in group B and2253.0±1472.0pg/ml in group C, andthat in group A was the lowest（P＜0.05）.The number of oocytes obtained ingroup A (5.0±3.6was fewest among the three groups（P＜0.05）, and thenumber of oocytes obtained（9.5±7.0vs8.6±5.4） was similar between group Band group C（P＞0.05）. The fetilization rate in group B（81.1%）was higher than that in group C（77.7%）（χ²=6.646，P＜0.05）, while that in group A（76.1%）was similar to group B and group C.The cleavage rates were tantamount（P＞0.05）.The number of viable embryos was2.58±2.63in group A,4.19±3.06ingroup B and4.10±2.88in group C, and that in group A was the fewest. Theviable embryo rate in group B （58.3%）was lowest, and that in group C（63.6%）was lower than group A（73.8%）. No significant differences were observed inimplantation rates, pregnancy rates, cycle cancellation rates and all embryoscryopreservation rates among the three groups. Embryo cryopreservation ratein group A （16.3%） was lowest and that in group B（40.2%） and in groupC（38.4%） were comparable.Conclusions:Part of the patients whose LH levels have been low during COS, areclosely monitored in the whole ovarian stimulation process without serum LHor P increasing, on the contrary some persons’ LH levels decrese because ofE2level rising.These patients could use the protocol without GnRHant, buttheir pregnancy rate is unsignificantly lower than that of persons usingGnRHant.While undergoing controlled ovarian stimulation without assisteddrugs, it’s necessary to closely monitor the hormone levels.If serum LH levels rise unclearly,0.125mg GnRHant could be used toprevent premature LH peak.In0.125mg group the clinical pregnancy rate andplanting rate rise up unobviously,and GnRHant consumption significantlyreduced with the cost reducing accordingly.So half quantity GnRHant waseffective for COS,then could be extended using clinically.