完整性PN有40%會發育到囊胚期胚胎
不完整性PN只有4%會發育到囊胚期胚胎
完整性PN發育囊胚期胚胎有43%會懷孕
不完整性PN發育囊胚期胚胎只有20%會懷孕
Z1 score的2PN胚胎解凍後有50%PN完整性
Z2,3score的2PN胚胎解凍後有1-20%PN完整性
結論: 解凍後原核核膜及核仁越清晰，胚胎品質越佳
http://humrep.oxfordjournals.org/content/23/4/819.full
Integrity rate of pronuclei after cryopreservation of pronuclear-zygotes as a criteria for subsequent embryo development and pregnancy
+Author Affiliations
- 3Correspondence address. Department of Gynecological Endocrinology and Reproductive Medicine, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany. Tel: +49-228-28714379; Fax: +49-228-2874651; E-mail:v.isachenko@yahoo.com
- Received August 27, 2007.
- Revision received December 14, 2007.
- Accepted December 31, 2007.
Abstract
BACKGROUND The aim of this study was to examine whether the integrity rate of pronuclei, after cryopreservation of pronuclear zygotes, could be a predictor of future embryo development and implantation.
METHODS Two-pronuclei stage zygotes (n = 862) were cryopreserved by aseptic rapid freezing in 15% ethylene glycol + 15% DMSO + 0.2 M sucrose with a 4-step exposure in 12% (v:v), 25, 50 and 100% rapid freezing solution for 2, 1, 1 min and 30–50 s, respectively, at room temperature, and then plunged into liquid nitrogen. Zygotes were rapidly warmed at a speed of 30 000°C/min and subsequently expelled into a graded series of sucrose solutions (1.0, 0.5, 0.25, 0.12 and 0.06 M) at 2.5 min intervals and in vitro cultured for 5 days. If embryos had developed to blastocysts on the 5th day, they were transferred to the recipients. The rest of the embryos were fixed for evaluation of chromatin.
RESULTS Zygote development, up to the expanded blastocyst stage, after in vitro culture, was 40%, if the integrity rate of pronuclei was high, and 4% if the integrity rate was low (P < 0.05). The pregnancy rate after transfer of the 5-day blastocysts depended on the pronuclear integrity rate: 43% (125 pregnancies aftertransfer of 291 blastocysts) for those with a high integrity, and only 1 in 5 (20%) for the few blastocysts which had shown a pronuclear low integrity rate (P< 0.05).
CONCLUSIONS Integrity rate of pronuclei after cryopreservation of pronuclear zygotes was a predictor of future embryo development and implantation: high integrity rate resulted in high pregnancy rate, while zygotes with low integrity rate of pronuclei after cryopreservation had low developmental potential.
Figure 3:
The same two-pronuclear zygotes scored as Z4: development appeared to be dependent on the post-thawing integrity rate of pronuclei (a and b) Fresh pronucleus, (c and d) pronucleus after thawing. Embryos after respective times in in vitro culture (e–m). Embryo stained by Hoechst 33342 (m). Note: immune fluorescence staining of embryo showed defective cleavage and deformation of nuclear chromatin
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