Embryotoxicity in vitro with extract of Indigofera suffruticosa leaves

Aqueous extract of leaves of Indigofera suffruticosa (AELIs) were studied for adverse effects in preimplantation mouse embryos. Two-cell mouse embryos were cultured for 94 h in human tubal fluid medium (HTF), and AELIs at a concentration of 5 or 10 mg/ml. On Day 4 of culture, morulae and blastocysts were collected for morphological analysis of blastomeres. We found that embryos exposed to the higher concentration of AELIs (10 mg/ml) did not develop and all embryos persisted at the two-cell stage. Those embryos exposed to the lower concentration (5 mg/ml) showed development until morula, blastocyst and hatched blastocyst stages that were similar to the controls. These results suggest that use of AELIs may be hazardous to humans who make use of it in folk medicine.     

Effects of 3H-thymidine on preimplantation mouse embryos in vitro

The effect of 3H-thymidine on in vitro development of preimplantation mouse embryos was studied. Two-cell and 4-8-cell embryos from B6CBA/F1 mice were continuously exposed to 3H-thymidine in medium containing 3H-thymidine in concentrations ranging from 10-500 nCi/ml. The effect of the radioactive precursor on embryo development to the blastocyst stage was studied by morphological observation, counting the blastocyst cell number and measuring 3H-thymidine incorporation. The continuous presence of 3H-thymidine significantly inhibited development of 2-cell and 4-8-cell embryos to the blastocyst stage. Embryos cultured from the 2-cell stage were more sensitive to 3H-thymidine than those exposed from the 4-8-cell stage. Even in morphologically normal blastocysts the cell number was significantly reduced. A 2 hr pulse of 100 nCi/ml 3H-thymidine at the blastocyst stage, did not affect the blastocyst formation or the blastocyst cell number and the amount of incorporated 3H-thymidine was sufficient to provide a reliable quantitation of DNA synthesis during the culture of preimplantation embryos in vitro. Continuous incubation with 3H-thymidine in order to measure DNA synthesis of preimplantation mouse embryos should be avoided when DNA synthesis is used as a means of evaluating toxic effect of an agent. Adverse radiation effects by 3H-thymidine on preimplantation mouse embryos during toxicity testing can be avoided by pulse labelling.     

Enhancement of methylmercury toxicity by L-cystine in cultured mouse blastocysts

Expanded mouse blastocysts incubated with 1 to 2 microM methylmercury (MeHg) in modified Eagle's basal medium (BME + AA), which contains amino acids, collapsed and degenerated within 24 h. In contrast, blastocysts incubated with the same concentration of MeHg in egg culture medium (ECM), which does not contain amino acids, survived and remained expanded as control embryos did. By systematically omitting each BME amino acid from BME + AA and adding each BME amino acid to egg culture medium, we determined that L-cystine (0.5 mM in BME + AA) was the component of BME + AA that was responsible for the enhancement of the toxicity of MeHg. The shortest incubation time during which the cystine-enhanced MeHg toxicity became irreversible was 2 h, and the addition of any of the neutral BME amino acids (except threonine) or non-BME neutral amino acids (alanine, glycine, or serine) during the 2 h incubation eliminated or reduced the cystine-enhanced MeHg toxicity. Basic amino acids (except histidine) were less effective in protecting embryos: Glutamine and lysine reduced the toxic effect only slightly, and arginine had no effect. DL-buthionine sulfoximine (7.5 mM), a specific inhibitor of glutathione, also reduced cystine-enhanced MeHg toxicity. It therefore appears that cystine enhances MeHg toxicity indirectly, at least in part, by stimulating the synthesis of cellular glutathione, which may in turn enhance MeHg transport. In the absence of cystine, 10 microM MeHg (2 h incubation) was necessary to cause the collapse and degeneration of all blastocysts treated.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同的培养方法对鼠胚体外发育的影响

目的比较鼠胚在不同的培养体系中的体外发育情况,探讨培养液的体积对体外培养的影响。方法把收集的小鼠2-细胞胚胎分成两组,A组于20μl培养液的微滴中培养,B组与50μl培养液的微滴中培养,观察胚胎发育情况。结果 96h后A、B组的囊胚形成率分别为83.64%和81.63%,差异无统计学意义(P>0.05)。结论适当体积的培养滴可促进胚胎的体外发育。     

In vitro culture of postimplantation hamster embryos

In vitro culture of intact rat and mouse embryos has been described extensively, but information on the culture of other species is sparse. The present study examined some culture requirements of early somite stage hamster embryos and assessed the embryotoxic effects of sodium salicylate (SS), a direct acting chemical and cyclophosphamide (CP), a proteratogen, on these embryos. Hamster embryos explanted on gestation days (GD) 8 and 9 were cultured in Waymouth's embryo-hepatocyte co-cultivation medium (WEHC), 70% McCoy's 5A medium-30% male rat serum (MMRS) or 100% male rat serum (MRS) for 24 hours under various oxygen concentrations. Embryos cultured GD 8 to 9 in the various media grew and differentiated much as they did in vivo, while embryos cultured GD 9 to 10 grew best in MMRS as compared to embryos at the same stage in vivo. Embryos exposed to SS in MMRS at concentrations of 250, 300, or 400 micrograms/ml showed dose related embryotoxicity which included CNS defects, absence of hind limb bud formation, and lack of axial rotation. Hamster embryos co-cultivated with pregnant hamster hepatocytes and treated with 2.5, 6.25 and 12.5 micrograms/ml of CP, showed dose-dependent toxicity when compared to co-cultivated controls. Hamster embryos develop extensively in culture over a 24 hour period. This system may therefore provide a valuable tool for evaluating the species differences of a variety of potential teratogens and embryotoxins and allow the comparison of these embryotoxic effects between rat, mouse and hamster during similar stages of organogenesis.     

Lectin reactivity of expanded mouse blastocysts after exposure to sera from women with unexplained recurrent spontaneous abortion

Embryotoxic factors existing in maternal sera may influence their effects via specific binding to, or alteration of cell surface molecules in the conceptus. This study was undertaken to determine the effects of sera from women with unexplained recurrent spontaneous abortion (URSA) on cell surface glycoconjugates of the early conceptus. Four cell stage embryos were cultured in medium supplemented with sera from women with URSA, from normal women, or in medium without serum. Developmental competence was assessed as the stage distribution of embryos advancing to during 96 h in culture. Hatched (expanded) blastocysts were stained with wheat germ agglutinin (WGA), peanut agglutinin (PNA) and dolichos biflorus agglutinin (DBA) to detect surface glucoconjugates. We observed that patient sera could be divided into high- and low-risk groups on the basis of the ability to decrease the number of four-cell embryos reaching the expanded blastocyst stage. Furthermore, the intensity of reactivity to PNA changed after exposure to high-risk sera. Morula formation was reduced and blastocyst formation was delayed. Although the sera from women with URSA had embryotoxic effects, no influence on the glycoconjugate patterns were evident in hatched blastocysts, aside from PNA reactivivity. We suggest altered developmental display of PNA-reactive proteins was a biomarker for poor developmental quality due to emrbyotoxic factors in serum from URSA patients.     

Interactive dysmorphogenic effects of toxaphene or toxaphene congeners and hyperglycemia on cultured whole rat embryos during organogenesis

Both diabetes mellitus and exposure to environmental contaminants are becoming health hazards to many indigenous populations in the world. In earlier work, we established the embryopathy of the chlorinated pesticide, toxaphene technical mixture (TOX) and its two physiologically most important congeners, T(2) (2-exo,3-endo,5-exo,6-endo,8,8,10,10-octachlorobornane) and T(12) (2-exo,3-endo,5-exo,6-endo,8,8,9,10,10-nonachlorobornane). In this study, the combined effects of toxaphene or its two congeners and high glucose concentrations were studied using rat embryo culture in order to investigate the potential interactions between hyperglycemia and toxaphene exposure. Whole rat embryos (0-2 somite) were explanted and cultured into a normal (8 mM) or hyperglycemic 12.5 mM (12.5 G) or 18.75 mM (18.75 G) culture medium containing TOX, T(2), or T(12) at various concentrations (0, 100, 1000, 5000 ng/ml) for 48 h at 37 degrees C. All treatments, except mild hyperglycemic exposure (12.5 G), had significant adverse effects on the total morphological score, head and crown-rump length, yolk sac diameter and yolk sac circulation. Embryos exposed to 18.75 G did not show malformations but when hyperglycemia at 18.75 G was combined with higher doses of TOX or T(2) synergistic effects on the incidence of neural tube defects were observed. The embryos cultured with T(12) under severe hyperglycemic conditions of 18.75 G showed an inhibition of T(12)-induced neural tube defects, but there was a concurrent underdevelopment of forelimbs or hindlimbs at the highest T(12) dose. The results suggest that there is a site-specific and dose-related interactive dysmorphogenesis elicited by TOX or its congeners with high levels of glucose on rat embryonic development. Because of the relatively high TOX doses used in this study, the drastic growth retardation and malformation observed are unlikely to be observed in human populations. More subtle effects, however, may not be ruled out.     

囊胚培养在体外受精和胚胎移植周期中的应用

目的 建立囊胚培养系统以提高人胚胎的种植率。方法 进行了１２个治疗周期的囊胚培养,在受精后进行胚胎体外培养至第５天,达囊胚期后移植。结果 共取卵１７７只,受精率６７％,囊胚形成率为４２％,囊胚种植率为１４％,并获３例临床妊娠。结论 囊胚培养为进一步提高临床成功率和开展种植前遗传学诊断创造条件,具有十分重要的应用前景。     

Expression of ganglioside GT1b in mouse embryos at different developmental stages after cryopreservation

Gangliosides are a family of sialic acid-containing glycosphingolipids that are abundant in neurons and have a variety of functions in developing and mature tissues. We examined the expression of ganglioside GT1b in the embryonic preimplantation stage after freezing and thawing processes to determine the regulatory roles of ganglioside GT1b in early embryonic development. ICR mouse embryos at the two-cell stage obtained by flushing the oviducts were frozen by two cryopreservation procedures, slow freezing using a programmable freezer or vitrification by direct plunging into liquid nitrogen. Slow freezing was conducted with equilibration in 1.5 M 1,2-propanediol or 5% equilibration glycerol. Vitrification was applied with a 10–15 min equilibration in 7.5% ethylene glycol (EG), 7.5% dimethylsulfoxide (DMSO), and 30 sec in a solution of 15% EG, 15% DMSO and 0.5 M sucrose. Immediately after thawing, the survival rate of the embryos was assessed by their morphology and ability to develop to blastocysts in culture. The survival rate of vitrified and thawed embryos (92%) was significantly higher than that of slow frozen and thawed embryos (76%) (P<0.05). A tendency of higher blastocyst rate was found in the vitrified and thawed embryos compared to that of the slow frozen and thawed embryos. Confocal immunofluorescence staining confirmed that surviving embryos expressed ganglioside GT1b, with the strongest expression at the compacted eight-cell or later stage embryos. Ganglioside GT1b was not observed in the TUNEL-positive, apoptotic embryos, suggesting that cryopreservation had induced DNA breaks in them. These results suggest that ganglioside GT1b may play an important role in embryo survival or development. These authors contributed equally to this work.     

Sensitivity of early mouse embryos to methylmercury toxicity

The sensitivity of early mouse embryos to mercury toxicity was studied in vitro by treating them with methylmercuric chloride (MMC) and examining their developmental potential. It was found that MMC exerted acute effects at high concentrations (1 to 2 μm) by arresting preimplantation development or by collapsing blastocoels. At a lower concentration (0.5 μm), MMC did not affect preimplantation development but interfered with development of the inner cell mass (ICM). The acute effect of MMC was most severe on blastocysts and least severe on morulae. When blastocysts were treated for 24 hr, 95 and 100% of them collapsed during treatment with MMC at 1 and 2 μm, respectively. Most of the collapsed blastocysts did not develop any further. By contrast, 32% (not significantly different from control) and 50% of morulae failed to develop into blastocysts during treatment with 1 and 2 μm MMC, respectively. The sensitivity of two-cell and four- to eight-cell embryos to the acute effect of MMC fell between that of morulae and blastocysts: When they were treated with 2 μm MMC, none of the embryos developed into blastocysts, but at an MMC concentration of 1 μm, 64% of two-cell embryos and 73% of four- to eight-cell embryos failed to form blastocysts. Delayed effects of MMC on trophoblast outgrowth and ICM development were also least severe after treatment of morulae but similar after treatment at all other stages. When two-cell embryos were exposed to MMC for 3 days or when late blastocysts were exposed for 5 days, 0.25 or 0.125 μm, respectively, was sufficient to interfere with development of the ICM. These results indicated that early mouse embryos are highly sensitive to mercury toxicity and that the sensitivity changes as they develop.     

In vitro exposure of male and female mice gametes to cadmium chloride during the fertilization process,and its effects on pregnancy outcome

The effect of cadmium chloride (Cd) on gamete fusion in vitro was evaluated, with further observations of the embryonic development and assessment of the pregnancy outcome of the in vitro fertilized mice. Oocytes were recovered from superovulated B₆C₃F₁ female mice and inseminated in vitro with spermatozoa from B₆C₃F₁ males. Of 1210 control oocytes, 53.2% cleaved into two-cell stage embryos. Of these, 46.6% developed into blastocyst stage embryos which were then surgically transferred to pseudopregnant female CD-1 mice. Of a total of 63 implanted embryos, 8 (12.7%) developed in utero to live fetuses. Teratological examinations of these “test-tube” mice revealed no signs of abnormalities caused by in vitro culture. Male and female gametes were exposed to 0.4, 0.8, or 1.6 μm of Cd and a decrease in sperm motility was noted in the 1.6 μm group. Nevertheless, even in the highest concentration used, 56.4% of the ova cleaved into the two-cell stage, thus indicating no effect of Cd on initial gamete interaction. Gametes that had been treated with 0.4 and 0.8 μm Cd developed to blastocysts at rates comparable to that of the controls. In the 1.6 μm group, however, only one (3.2%) of the two-cell embryos developed to the blastocyst stage. Blastocysts from 0.4 μm Cd-treated gametes were then transferred to surrogate dams. Statistically significant blastocyst losses were recorded during the implantation period, whereas the pregnancy rate and the numbers of resorbed and live fetuses, were comparable to those of the controls. The offspring exhibited no malformations, and their body weights remained within the control values.     

Oxidative stress status and development of late organogenesis stage rat whole embryos cultured from gestational days 13.5 to 14.5.

A new method for culturing rodent whole embryos at the late organogenesis stage was developed using a roller-bottle system with intermittent gassing. Rat embryos were cultured for 24 h from gestational day (GD) 13.5 to 14.5. Growth and metabolic comparisons were made between in vivo embryos and embryos of the same GD cultured under various media and conditions. Crown-rump length, head length and protein content were used as growth indicators. Biologic markers such as embryonic tissue concentration of glutathione (GSH), glutathione disulfide (GSSG) and lipid peroxidation were used as assessments of metabolic activity in terms of oxidative stress. Embryos cultured with media consisting of either 15% or 20% male rat serum and balanced with Dulbecco's Modified Eagle Medium (DMEM) were found to most closely match in vivo embryos. 6 h gassing intervals and 5 mL medium volume/embryo provided optimal conditions for cultured embryos. By shortening the 24 h embryo culture period to 12 h, embryonic haemorrhaging was avoided. Moreover, the 12-h cultured embryos showed similar redox GSH/GSSG ratios and similar GSH content to the in vivo embryos, which was not observed in the embryos cultured under 24 h culture conditions. The present work demonstrates the utility of late organogenesis stage embryo culture as a model for the assessment of in vivo embryonic growth and oxidative stress indices.     

Cleavage and development in cultured preimplantation mouse embryos exposed to lidocaine

Two-cell preimplantation mouse embryos were exposed in vitro to lidocaine (0 to 1,000 μg/mL) for 72 h to determine the effects of this anesthetic on subsequent cleavage and development during prolonged exposures. Embryonic development was monitored each 24 h for 3 d. Lidocaine adversely affected the in vitro development of the mouse embryos, altering the distribution of the development stages at the evaluated culture tunes. The percentage of two-cell embryos that cleaved and developed to more advanced stages was decreased by the exposure to lidocaine. After 24 h of culture, two-cell embryos were arrested before completion of cellular division; this occured in 30% of the embryos at concentrations of 10 to 100 μg/mL and in 73.2% of the embryos with 1,000 μg/mL. After 48 h the blastomeres of the arrested embryos began to degenerate, showing lysis or fragmentation. At the lowest concentration, 14.9% of the arrested embryos exhibited the capacity to recover. These embryos continued their cleavage and normal development towards blastocyst formation. The cytotoxic effect and arrest at the two-cell stage were observed in a dose-dependent manner after 72 h of culture. We conclude that sensitivity to lidocaine embryotoxicity occurs during a window at the two-cell stage.     

Development and sister chromatid exchange of mouse morulae and blastocysts cultured in rat serum containing active metabolites of cyclophosphamide

To establish an in vitro test system in which sera from animals treated with various chemicals can be tested for embryotoxic effects during the preimplantation period, mouse morulae and blastocysts were cultured in the presence of rat serum (RS) from animals which had been treated with cyclophosphamide (CPA). Development during in vitro culture for 96 h, cell number, chromosomal aberrations and sister chromatid exchange (SCE) were the end-points tested in exposed embryos. SCE frequency was the most sensitive parameter, indicating embryotoxic effects in preimplantation mouse embryos after only 1 h of exposure to RS-CPA.     

不同质量胚胎囊胚培养比较以及对妊娠结局的影响

目的:探讨不同质量胚胎进行囊胚培养的情况以及移植后对妊娠结局的影响。方法:收集2018年1月—2019年12月太原市中心医院生殖中心行常规体外受精/卵胞浆内单精子显微注射-胚胎移植(IVF/ICSI-ET)助孕且进行囊胚培养的患者资料,根据囊胚培养前胚胎质量分为优质胚胎囊胚培养组(A组)与非优质胚胎囊胚培养组(B组),比较两组患者一般情况、囊胚培养情况以及妊娠结局。结果:共156个周期患者资料,两组年龄、体质量指数(BMI)、不孕年限、基础雌二醇(E₂)、基础促卵泡激素(FSH)、子宫内膜厚度等一般资料比较,差异无统计学意义(P>0.05)。囊胚培养结果显示,A组囊胚形成率和可利用囊胚形成率都高于B组(P<0.05)。妊娠结局显示,两组移植胚胎数、临床妊娠率比较,差异无统计学意义(P>0.05),但A组多胎率高于B组(P<0.05)。结论:优质胚胎囊胚培养形成率及可利用囊胚率优于非优质胚胎,但临床妊娠率无差异,只是优质胚胎囊胚培养移植后多胎率较高,临床可对非优质胚胎进行囊胚培养以提高临床妊娠率。     

Action of allopurinol and aspirin on rat whole-embryo cultures.

The effects of allopurinol (HPP) at concentrations ranging from 0.33-1.83 mM and of aspirin (ASA) from 0.28-2.22 mM, were studied on the rat whole-embryo culture system. Embryos were explanted at day 10 of gestation and cultured for 48 h, either in the absence or in the presence of rat and human S9. HPP proved to be potentially embryolethal and teratogenic without any S9, while it was embryolethal with rat S9 and dysmorphogenic with human S9. ASA showed an embryolethal and teratogenic potency without any S9 samples. These responses were increased in the presence of rat S9, while ASA embryolethality was predominant with human S9. These results obtained on rat embryos in culture suggest a correlation between the species origin of the biotransforming system and the known teratogenicity of HPP in sensitive animal models. However, ASA elicited responses not in agreement with the known teratogenic response in rodents.     

Preimplantation exposure to bisphenol A advances postnatal development

Prenatal exposure to bisphenol A (BPA), an estrogenic compound, has been shown to alter postnatal development at an environmentally relevant exposure level. To elucidate these low dose effects of preimplatation exposure to BPA, two-cell mouse embryos were cultured with 1 nM BPA. More embryos exposed to 1 nM BPA than controls reached the blastocyst stage. When the blastocysts with or without BPA exposure were transferred to uterine horns of pseudopregnant recipient mice not treated with BPA, the number of pups per litter and body weight at birth did not differ. At weaning on postnatal day 21, however, pups treated with 1 nM BPA during the preimplantation period were significantly heavier than controls. These findings suggest that BPA may not only affect early embryonic development even at low, environmentally relevant doses, but also may exert late effects on postnatal development.     

Abnormal neurulation induced by 7-hydroxy-2-acetylaminofluorene and acetaminophen: evidence for catechol metabolites as proximate dysmorphogens

Direct additions to culture media of either acetaminophen (APAP) or 7-hydroxy-2-acetylaminofluorene (7-OH-AAF) resulted in abnormal closure of the anterior neuropores of cultured rat embryos in the absence of an exogenous bioactivation system. Concentrations required to produce a 50% incidence of the defect were approximately 500 and 250 microM for APAP and 7-OH-AAF, respectively. Losses of viability were not evident at these concentrations but 7-OH-AAF elicited a somewhat greater effect on growth parameters and generalized embryotoxicity. Transplacental induction with 3-methylcholanthrene (MC) of P450IA1 in subsequently cultured rat embryos did not detectably alter the capacity of APAP or 7-OH-AAF to effect embryotoxicity or neuropore closure. However, additions to the culture medium of exogenous hepatic bioactivating systems (S9) from MC-induced vs phenobarbital (PB)-induced adult rats produced profoundly different effects on neuropore closure. Coincubation with S9 from MC-induced rats reduced the incidence of 7-OH-AAF-elicited abnormal neuropores from 45 to 19%, whereas coincubation with S9 from PB-induced rats increased the incidence to 77%. Coincubation with MC-induced S9 produced no statistically significant effect on APAP-elicited neuropore abnormalities but, with PB-induced S9, resulted in a significant increase from 60 to 86%. Additions of 3-OH-APAP (0.1-0.2 mM) but not N-acetyl-p-benzoquinoneimine (NAPQI, 0.1-0.5 mM) to the culture medium elicited the typical neuropore abnormality. Experiments with APAP and 7-OH-AAF as substrates demonstrated that embryonic enzymes catalyzed their conversion to the corresponding catechols. Considered together, the results provided evidence that embryonic conversion of APAP or 7-OH-AAF to the corresponding catechol metabolites may be instrumental in effecting the abnormal anterior neuropore closure observed after exposure of embryos to the respective parent compounds.     

The antiestrogen ICI 182,780 abolishes developmental injury for murine embryos exposed in vitro to o,p'-DDT(1)

Previously, we reported that in vitro exposure of murine embryos to 0.1 microg/ml o,p'-DDT (an estrogenic pesticide) significantly reduced development to blastocyst and mean cell number per embryo, and increased percent cell death by 96 h of culture. The objective of the present study was to determine if developmental injury induced by o,p'-DDT resulted from estrogenic, antiestrogenic, or unrelated adverse biologic mechanisms. Toward this objective, pronuclear embryos from CD-1 mice were cultured 96 h in medium supplemented with 0.1% ethanol (control) or 0.1 microg/ml o,p'-DDT, 17beta-estradiol, or ICI 182,780 dissolved in ethanol as single agents or as paired mixtures. As single agents, development to blastocyst and mean cell numbers were significantly reduced and percent apoptosis was significantly increased for embryos cultured in the presence of o,p'-DDT or ICI 182,780. Development to blastocyst was significantly reduced for embryos cultured in the presence of 17beta-estradiol. Beneficial interaction occurred when the receptor antagonist ICI 182,780 was combined with either receptor agonist (o,p'-DDT or 17beta-estradiol). In contrast, interaction was not significant when the two agonists were combined. The results indicate that developmental injury due to the estrogenic pesticide o,p'-DDT was abolished by the addition of the receptor antagonist ICI 182,780 and not by the receptor agonist 17beta-estradiol. The findings underscore the utility of the model for uncovering mechanisms of developmental injury.     

卵裂期胚胎玻璃化冷冻解冻后继续培养至囊胚的妊娠结局分析

目的了解卵裂期胚胎玻璃化冷冻解冻后行囊胚培养的妊娠结果。方法回顾性分析2013年5月-2013年9月在郑州大学第二附属医院生殖中心行玻璃化冷冻解冻后移植的患者共202周期的妊娠情况;其中卵裂期胚胎冷冻解冻后移植者136周期,卵裂期胚胎解冻后行囊胚培养后移植者66周期。结果卵裂期胚胎冻融移植者136周期,均有胚胎可移植,获得妊娠45周期,妊娠率为33．08％（45／136）、着床率为17．35％（55／317）,早期流产率为17。78％（8／45）;卵裂期胚胎解冻后行囊胚培养者66周期212个胚胎,其中43个周期共形成囊胚87个,囊胚形成率为41．03％（87／212）、获得妊娠22周期,妊娠率为51．16％（22／43）、着床率为32．94％（28／85）、早期流产率14．29％（3／22）。囊胚期移植者的着床率及临床妊娠率显著高于卵裂期移植者,差异有统计学意义（P〈0．05）。结论卵裂期胚胎解冻后培养至囊胚能获得较高的着床率和妊娠率。