Investigation About The Influence Of Gonadotrophin Starting Time After Pituitary Desensitization During Long Down Regulation Protocol Of IVF-ET

Objective：The relationship was analyzed which was about different outcomes of in-vitrofertilization and embryos transfer in terms of pituitary down-regulation days, estradiol（E₂） level or luteinizing hormone （LH） level, to offer more clinical evidences forexacter gonadotrophin starting time.Method：The data of119patients was retrospectively analyzed which had undergone in-vitrofertilization treatment from March to August2010in the reproductive medicinecenter. Statistical analysis was accomplished by SPSS17.0package.Result：1. For different pituitary down-regulation days groupsThe LH levels on gonadotropin starting day was different between two groups（P<0.05）, and dropped as the days put off. Fertilization rate and embryo implantationrate of two groups was not statistically different. The difference about the otheroutcomes of in vitro fertilization between groups was not statistically significant.2. Groups for different LH level on gonadotropin starting dayGroup A_Ⅰ’s embryo implantation rate was23.81%, lower than the group A_Ⅱ’s（34.47%）or groupA_Ⅲ’s（34.19%）（P=0.54）. The pregnancy rate of group A_Ⅱwasthe highest, but the difference among the three groups was not statistically significant.3. Groups for different estradiol level on gonadotropin starting dayThe average numbers of retrieved ovums were different significantly between groupsB_Ⅰ16.47±7.72and B_Ⅱ13.71±6.72（P<0.05）. Cancellation rate of transplantation ofgroup B_Ⅰwas higher than the other groups, but the difference was not statisticallysignificant. The difference of the pregnancy rates between two groups was notstatistically significant.Conclusion：a. This study suggests that the longer GnRH-duration, the deeper suppressive effectto pituitary. But different pituitary down-regulation days may not affect the outcomes of IVF-ET.b. Too low LH level on gonadotropin starting-day may pull the endometrialreceptivity on pre-implantation down. An appropriate level of LH is necessary.c. Too low estradiol level on gonadotropin starting-day may lead to overdose andtoo much follicles, followed high estradiol level, and an even higher OHSS rate, orhigh cycle cancellation rate because of low reaction of ovaries.d. Before giving gonadotropin, the pituitary down-regulation days, and the LH leveland estradiol level on gonadotropin starting-day should be comprehensivelyconsidered.