title: Effects of trehalose vitrification and artificial oocyte activation on the development competence of human immature oocytes.
abstract: Sucrose and trehalose are conventional cryoprotectant additives for oocytes and embryos. Ethanol can artificially enhance activation of inseminated mature oocytes. This study aims to investigate whether artificial oocyte activation (AOA) with ethanol can promote the development competence of in vitro matured oocytes. A total of 810 human immature oocytes, obtained from 325 patients undergoing normal stimulated oocyte retrieval cycles, were in vitro maturated (IVM) either immediately after collection (Fresh group n = 291)) or after being vitrified as immature oocytes (Vitrified group n = 519). These groups were arbitrarily assigned. All fresh and vitrified oocytes which matured after a period of IVM then underwent intra-cytoplasmic sperm injection (ICSI). Half an hour following ICSI, they were either activated by 7% ethanol (AOA group) or left untreated (Non-AOA group). Fertilization, cleavage rate, blastocyst quality and aneuploidy rate were then evaluated. High-quality blastocysts were only obtained in both the fresh and vitrified groups which had undergone AOA after ICSI. Trehalose vitrification slightly, but not significantly, increased the formation rates of high-quality embryos (21.7% VS 15.4%, P > 0.05) and blastocysts (15.7% VS 7.69%, P > 0.05)) when compared with sucrose vitrification. Aneuploidy was observed in 12 of 24 (50%) of the AOA derived high quality blastocysts. High-quality blastocysts only developed from fresh or vitrified immature oocytes if the ICSI was followed by AOA. This information may be important for human immature oocytes commonly retrieved in normal stimulation cycles and may be particularly important for certain patient groups, such as cancer patients. AOA with an appropriate concentration of ethanol can enhance the developmental competence of embryos.
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China; Insititute of Reproduction and Genetics of Anhui Medical University, Hefei 230022, China; Biopreservation and Artifical Organs, Anhui Provincial Engineering Research Center, Hefei 230022, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Tianjuan
authors.initials: T
authors.lastname: Wang
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Center for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui, China.
authors.forename: Fazil
authors.initials: F
authors.lastname: Panhwar
authors.affiliation: Center for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui, China.
authors.forename: Zhongrong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zou
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Ji
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Beili
authors.initials: B
authors.lastname: Chen
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhou
authors.affiliation: Center for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui, China. Electronic address: ZhaoG@ustc.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Reproductive Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China. Electronic address: caoyunxia6@126.com.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000782:Aneuploidy; D001755:Blastocyst / Q000502:physiology; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques; D009865:Oocytes / Q000254:growth & development*; D009866:Oogenesis / Q000502:physiology; D020554:Sperm Injections, Intracytoplasmic; D013395:Sucrose / Q000494:pharmacology*; D014199:Trehalose / Q000494:pharmacology*; D058989:Vitrification
chemical_list: D003451:Cryoprotective Agents; D000431:Ethanol; D013395:Sucrose; D014199:Trehalose
keywords: Aneuploidy; Artificial oocyte activation (AOA); Fluorescence in situ hybridization (FISH); Human immature oocytes; Trehalose vitrification