| BACKGROUD:Because ovarian stimulation is considered essential for assistedreproduction in order to obtain sufficient oocytes for fertilization, andnot only one best quality embryos is transferred into the uterus,theincidence of multiple pregnancies has risen at an unprecedented pace overthe past 2 decades. Multiple births are the most frequent complication ofIVF ,it is harm to the nation ,the society ,the family and also mather andfetus.Wheather reduce the number of transferred embryos can reduce themultiple gestation and stabilize the pregnancy rate?The availability of sequential culture media that are tailored toembryo requirements at various stages of development has madeextended culture of embryos until the blastocyst stage feasible. Delayingembryo transfer until day 5 or 6 of in vitro culture, when the embryo hasreached the blastocyst stage of development,has some theoreticaladvantages that may improve the success of embryo transferprocedures.Extended culture allows better identification of thedevelopmental potential of embryos because only a small percentage ofembryonic genes are activated by day 2 or 3 of culture.Owing to the factthat human embryos normally reside in the fallopian tube in their earlystages of development and do not implant until after compaction, theuterine environment is also better able to cater for the nutritional requirements of a blastocyst than a cleavage-stage embryo.PART ONEOBJECTIVE: We analyze the influences of different numbers oftransferred good quanlity embryos to multiple gestation rates when inpatients of different female age and cycles in order to fred the optimalstrategy——the number of transferred embryos can reduce the multiplegestation and stabilize the pregnancy rate.MATERIALS AND METHODS: In this retrospective study, a total of4672 patients who received ovarian stimulation and transferred embryowas analyzed between Jan. 2004 and Nov. 2006.In these patients,the totalmultiple gestation rates was 28.59%. According to the transferred goodquanlity embryos,the patients are devided into 3 groups: 1, 2 and 3;according to the female age and treatment cycles,the patient are devidedinto:＜35years old,＜3times:＜35 years old,≧3 times;≧35 yearsold,＜3 times;≧35 years old,≧3 times.RESULTS: 1.The multiple gestation rates of the groups that transferred1 good quality embryos,2 good quality embryos, 3 good quality embryoswere 19.88% (32/161), 31.49% (409/1299), 44.37% (63/142) in womenage＜35,cycles＜3,there were significant differences between them.Thepregnancy rates of these groups were 29.65%(161/543),51.69%(1299/2513), 54.41%(142/261) in women age＜35, cycles ＜3,there were no significant differences between 2 good qualitytransferred embryos groups and 3 good quality transferred embryosgroups. 2.The multiple gestation rates of the groups that transferred 1good quality embryos,2 good quality embryos, 3 good quality embryoswere 20.00％(8/40), 20.69％(18/87), 42.33％(69/163)in women age≥35,cycles＜3, there were no significant differences between 1 good qualitytransferred embryos groups and 2 good quality transferred embryosgroups.The pregnancy rates of these groups were 20.41％(40/196),34.66％(87/251), 42.34％(163/385) in women age＞35, cycles＜3,therewere no significant differences between 2 good quality transferredembryos groups and 3 good quality transferred embryos groups.CONCLUSION: The transfer of 2 good quality embryos resulted insimilar pregnancy rates and significantly reduced multiple gestation rateswhen compared to the transfer of 3 good quality embryos in womencycles＜3.PART TWOOBJECTIVE: in this part,the aim is to find wheather the multiplegestation rates change result from the change of pregnancy rates in ourhospital.MATERIALS AND METHODS: a total of 2321 patients whoreceived ovarian stimulation and transferred embryo was analyzed in 2002,2004 and Nov.and Dec. 2006.RESULTS: there are no significant differences of multiple gestationrates among different years when the pregnancy rate are differentregardless of the number of transferred good quality embryos.CONCLUSION:there are no relationship between the multiple gestationrates and pregnancy rates.PART THREEOBJECTIVE: In this part, we analyze the influences of total goodquanlity embryos and total follicles to multiple gestation rates andpregnancy rates in order to fred the probable indication of blastocystculture and transfer in elective patients.MATERIALS AND METHODS: In this retrospective study, a total of4672 patients who received ovarian stimulation and transferred embryowas analyzed between Jan. 2004 and Nov. 2006.In these patients,the totalmultiple gestation rates was 28.59％.We describe the change of multiplegestation rates and pregnancy rates under different patients who obtained1,2,3……≥26 total follicles,and 1,2,3,……≥15 total good qulityembryos.RESULTS: The pregnancy rates and the multiple gestation ratesbecome stable when the number of total follicles is up to 9.Thepregnancy rates become stable while the multiple gestation rates still go high when the number of total good quality embryos up to 3.CONCLUSION: The results suggest that the patients shoule notobtain too much follicles to get pregnancy rates in ART.The doctors canpropose the patients have blastocyst culture and transfer when they havemore than 9 follicles or 3 good qulity embryos. |
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