1、新新鲜周期或冻融周期移植鲜周期或冻融周期移植 这是个问题？这是个问题？新鲜与冻融周期移植历史发展与目前趋势the first pregnancy of a thawed cryopreserved human embryo was reported in 1983 in Australia,and the first live birth in 1984 in The Netherlands1988年AFS(ASRM)的IVFspecial interest group(SART)首次报告1985至1986年ART数据：822个总妊娠中7个FET妊娠，FET小于1%In 1995,SART c
2、ollaborated with CDC to publish data:1282 FET births among12000 deliveries,FET10%In 2012,15408 FET births,accounting 1/3 ART births新鲜与冻融周期移植历史发展与目前趋势新鲜与冻融周期移植历史发展与目前趋势 Initially,owing to low success rate,all available embryos were transferred in IVF treatments,that is to say,fresh ET almost always c
3、oincided with stimulation improvements of clinical and laboratory aspects of IVF(multiple follicular stimulations,egg retrieval,culture conditions)increased pregnancy rates increased risk of multiple pregnancies fewer embryos transferred supernumerary(second best)embryos need to be cryopreserved dra
4、matic improvement in cryopreservation of eggs and embryosSegmentation of IVF process such that embryo replacement is avoided during the cycle of ovarian stimulation and egg retrievalCohort cryopreservation in case of OHSS etc.Embryonic/endometrial asynchrony might also be handled by cryopreservation
5、 and delayed ETPGS with trophectoderm biopsy requiring freezing embryos to allow time for genetic analysis.Cohort banking is routine after the use of a GnRH agonist trigger Accumulation of eggs/embryos over multiple cycles as a strategy for managing low responder patients 新鲜与冻融周期移植历史发展与目前趋势segmentat
6、ion of IVF process such that embryo replacement is avoided during the cycle of ovarian stimulation and egg retrieval Embryo donation programs Embryo banking Fertility preservation for whom gonadotoxic chemotherapy is planned or are wishing to delay pregnancy for more than 1 years新鲜与冻融周期移植历史发展与目前趋势超排
7、导致的非（超）生理围植入期环境的影响 Superovulation is an integral part of IVF and results in supraphysiologic levels of multiple hormones and other factors,including E2,P,and VEGF etc.Forming a non(supra)physiologic(peri-implantation)environment during oocyte development and after embryo transfer,having multiple eff
8、ects to oocyte,endometrium,and implanting embryoEffect on oocyte超排导致的非（超）生理围植入期环境的影响Effect on endometrium植入窗期内膜 腺体显示核下空泡 腺上皮表面出现胞饮突 内膜核仁通道系统出现动物实验显示超排卵影响 表面上皮深度 微绒毛的数目和深度 表面上皮与基质细胞有丝分裂活性IVF取卵日子宫内膜活检研究显示多数样本内膜提前，年轻及获卵数多提前更明显超排导致的非（超）生理围植入期环境的影响Effect on endometrium超排导致的非（超）生理围植入期环境的影响Effect on endome
9、trium超排导致的非（超）生理围植入期环境的影响Groups I and II showed a secretory activity of the endometrium on the day of oocyte retrieval,the high P group showing a mean maturation advance of 0.7 day(P 3 days.Effect on endometrium the timing of P exposure differs in a fresh cycle,the premature elevations in P often se
10、en during stimulation in a fresh cycle do not occur in a frozen cycle elevations of P during superovulation(before hCG administration),shifting the time period that the endometrium is receptive to the implanting embryoEffect on endometrium 内膜容受窗的移动（shift）影响妊娠，提前超过3天与植入失败相关超排导致的非（超）生理围植入期环境的影响（一定水平的雌
11、激素有利于妊娠，但雌激素水平过高会降低妊娠率）（一定水平的雌激素有利于妊娠，但雌激素水平过高会降低妊娠率）Effect on endometrium超排导致的非（超）生理围植入期环境的影响Effect on endometrium超排导致的非（超）生理围植入期环境的影响Effect on endometrium超排导致的非（超）生理围植入期环境的影响women with a PE of 0.81.1 ng/mL had a lower chance of pregnancy compared with women with progesterone levels 0.8 ng/mL(odds
12、ratio OR 0.79,95%confidence interval CI 0.670.95)no effect of PE on pregnancy chances was observed when embryos resulting from women exhibiting PE on the day of hCG were cryopreserved and transferred in a subsequent cycle(OR 1.03,95%CI 0.791.34)The same results hold for embryo transfers in donor-rec
13、ipient cycles(OR 1.18,95%CI 0.761.84)Effect on endometrium超排导致的非（超）生理围植入期环境的影响 Pregnancy rates were not decreased when these embryos were transferred in subsequent frozen-thaw or in donor-recipient cycles,demonstrating the detrimental effect of the elevated P is on the endometrium,not the embryoEffe
14、ct on endometrium超排导致的非（超）生理围植入期环境的影响D5囊with COS VS D6囊 with COS 高 VS D6囊 w/o COS 无差异D5囊w/o COS VS D6囊 with COS 高 VS D6囊 w/o COS 无差异D6囊Fresh ET VS D6囊 FET 低Shared oocytes供卵者自身鲜周期妊娠率 VS 受卵者妊娠率 低 （with COS）(w/o COS)Effect on endometrium超排导致的非（超）生理围植入期环境的影响内膜组织学提前（年轻、卵多）PE胚胎发育慢Effect on endometrium超排导致
15、的非（超）生理围植入期环境的影响超排导致的非（超）生理围植入期环境的影响Effect on endormetrial immue 子宫内膜免疫在种植中发挥重要作用，现已证实NK细胞、血管内皮生长因子（VEGF）和内膜容受性相关种植发生时，NK 细胞分泌白介素-15将NK细胞转化为蜕膜NK细胞，其分泌多种因子包括血管生成因子如VEGF、活化因子、生长因子如LIF，对种植是重要的超排导致的非（超）生理围植入期环境的影响Effect on endormetrial immue 小鼠实验（NK细胞）：Percentage of total NK cells(CD56+CD3)on all endome
16、trial cells(a)and percentage of CD56brightCD16-on total NK cells(b)as assessed by flow cytometry in endometrial biopsies from fertile oocyte donors in natural and ovarian stimulated cycles with and with-out local injury treatment.*P 150 genes,including genes regulating angiogenesis and early implant
17、ation.(人体研究人体研究)对促排卵周期供卵者和自然周期进行内膜活检，结果显示，二者间有150个基因表达存在差异，其中很多基因在血管生成和早期种植方面有重要作用。对子宫内膜相关基因表达的影响对宫外孕发生的影响有认为IVF鲜周期妊娠的EP风险高于自然妊娠，部分原因是雌激素对子宫收缩的作用及PE对cilia的影响超排导致的非（超）生理围植入期环境的影响Effect on implanting embryoextension of the Barker hypothesis 1995年，巴克提出“成人疾病的胎儿起源”假说（Fetal origins of adult disease，FOAD），
18、即著名的“巴克假说”（Barker hypothesis），后发展成“健康和疾病的发育起源（DOHaD）”的理论。in utero stress may affect childhood development and propensity to adult disease Said another way,health at the time of or even before conception(periconceptional events)may affect in utero and childhood development,predisposition for adult di
19、sease.Naturally conceived blastocysts were flushed and transferred to pseudopregnant females after either natural mating(control)or gonadotropin administration and mating(experimental),Pregnant mice were then sacrificed near term(embryonic day 19)and the resultant placentas and fetuses isolated超排导致的
20、非（超）生理围植入期环境的影响Effect on implanting embryoeffect of superovulation on Embryonic Development and Fetal Growth体外研究：将小鼠胚胎置于育龄期妇女内膜中，并使胚胎暴露于高剂量雌激素环境中，最终导致胚胎发育受损及粘附力下降超排导致的非（超）生理围植入期环境的影响Effect on implanting embryo人体研究：高雌激素水平增加与异常胎盘形成有关的妊娠并发症的风险-除OHSS外还要关注的一个问题超排导致的非（超）生理围植入期环境的影响Effect on implanting emb
21、ryo超排导致的非（超）生理围植入期环境的影响Effect on implanting embryo超排导致的非（超）生理围植入期环境的影响Effect on implanting embryo与COS exposure后的鲜周期移植有关的风险包括pre-eclampsia,low birth weight(LBW),small for gestational age(SGA),prematurity,preterm LBW,antepartum hemorrhage,placental abruption,and perinatal deathmeta-analysis reported t
22、hat,when compared with fresh-transfer pregnancies,FET pregnancies were associated with significantly reduced risks of preterm birth(RR 0.84),SGA(RR 0.45),LBW(RR 0.69),perinatal mortality(RR 0.68),placental abruption(RR 0.44),and placenta previa(RR 0.71).Risks of very preterm birth,very LBW,congenita
23、l anomalies,and neonatal intensive care did not differ significantly.Increased risk of cesarean section delivery was observed with FET(RR 1.10).FET was associated with reduced risk of preterm birthAn Australian registry study compared birth defects after fresh transfers and FET with fertile controls
24、,and found fresh transfer had increased risk for birth defects when compared with fertile controls,but found no significantly elevated risks with FET vs.fertile controls.Another Australian study of 6,946 birth outcomes found that the risk of blastogenesis birth defects was significantly greater afte
25、r fresh transfer when compared with spontaneous pregnancies,but that births after FET did not exhibit this increased risk超排导致的非（超）生理围植入期环境的影响Effect on implanting embryoA relatively small clinical study comparing fresh transfer and elective cohort cryopreservation followed by FET in high responders f
26、ound reduced risk of pre-eclampsia with FET.An American registry study compared singleton births resulting from fresh autologous cycles,autologous FET,fresh oocyte donation cycles,and donor FET and found increased risk of LBW in fresh cycles when compared with FET.However,when fresh donor cycles wer
27、e compared with donor FET,no such differences were observedOne retrospective clinical study compared singleton births resulting from 2,531 fresh transfers and 4,092 FETs.This study used minimal stimulation(CC in combination with low-dose Gn)and single embryo transfer.No significant differences in pr
28、ematurity,total birth defects,or perinatal mortality were found,but greater birth weight and reduced incidences of LBW and SGA with FET were reported.超排导致的非（超）生理围植入期环境的影响Effect on implanting embryo超排导致的非（超）生理围植入期环境的影响Effect on implanting embryoEpigenetic Changes to the Embryo Studies of mouse oocyte
29、s have shown that superovulation has an effect not only on the methylation of the developing oocyte,but also on the developing embryo,with loss of methylation in select imprinted genes seen after superovulation Loss of methylation owing to a nonphysiologic uterine environment may have effects on pla
30、centation and fetal growthdisadvantages of cryopreservationpossibly altered embryo competence and subsequent implantationincreased spindle abnormalities have been demonstrated in(day 5)vitrified blastocysts compared with fresh blastocystsGenes involving the apoptosis/stress pathway(BAX),pluripotency
31、 pathway(NANOG,SOX2,CDX2),maternal effect genes(ZAR1,EIF1AX,TSC2)were significantly altered in frozen-thawed embryos compared with freshly cultured embryos from the same developmental stagebe cryopreserved at all stages of preimplantation developmentMethod of cryopreservationif clinic uses very stri
32、ct criteria,i.e.,only top-quality embryos are cryopreserved,their success rates after FET will be higher compared with a clinic with lower cut-off criteria.however,they will conduct fewer FET cycles per initiated fresh cycle and thus in aggregate the contribution of cryopreservation to their cumulat
33、ive success rates,i.e.,the chance of live birth per initiated cycle is likely to be lowerCriteria for judgement to frozen-thaw survival and transferExtended culture after thawingdisadvantages of cryopreservationCost from freezing procedure and the medications and monitoring required in some FET prot
34、ocolsTimestressin the near absence of OHSS risk,esp after agonist trigger,it may be tempting to increase Gn dose to maximize oocyte yielddisadvantages of cryopreservationIt is nave to say that supraphysiologic environment is all simply related to estrogen levels,even if estrogen levels are an approp
35、riate surrogate marker for other molecular changeswe do not know at what threshold a cycle becomes supraphysiologic.;whether supraphysiologic conditions result from the use of Gn(at any dose);whether alterations occur only when stimulation threshold has been exceeded?结语结语Whether modifications,such a
36、s low-dose superovulation or the use of VEGF-modifying agents,such as cabergoline,after ovulation trigger,have an effect on placentation and perinatal outcome will not be known until further research,both clinical and translational,is performed.Until then,preferentially cryopreserving embryos and tr
37、ansferring them into a more physiologic environment can reduce at least some of the risks associated with ART.Although we recognize that frozen embryo transfers may not be feasible or necessary for all patients,this approach appears to be an efficient way to decrease morbidity for patients at high r
38、isk for adverse outcomes,particularly those with high E2 levels,early PE and high risk for OHSS.Optimally,dramatic changes in the practice of medicine should be evidence based However,practice is already shifting,often the practice of medicine moves before definitive evidence is obtained.So we should interrogate the evidence continuouslyTime,and hopefully high-quality research will establish if we are ready to eliminate the transfer of fresh embryos in IVF.结语结语 坚决拒绝 不做 半推半就 不得不做 欲拒还迎 想做 投怀送抱？要做
