ABSTRACT
OBJECTIVE: The goal of this study was to ascertain optimal assisted hatching (AH) method in frozen embryo transfer. We compared the effect of depending on whether mechanical or laser-AH was performed before or after the vitrification of embryo development rate and blastocyst cell numbers. METHODS: In order to induce superovulation, pregnant mare's serum gonadotropin followed by human chorionic gonadotropin were injected into 4- to 5-week-old female mice. 2-cell embryos were then collected by flushing out the oviducts. The Expanded blastocysts were recovered after the collected embryos were incubated for 48 hours, and were then subjected to artificial shrinkage (AS) and cross-mechanical AH (cMAH) or quarter-laser zona thinning-AH (qLZT-AH) were carried out using the expanded blastocysts before or after vitrification. After 48 hours of incubation, followed by vitrification and thawing (V-T), and blastocysts were fluorescence stained and observed. RESULTS: The rate of formation of hatched blastocysts after 24 and 72 hours of incubation was significantly higher in the AS/qLZT-AH/V-T group than in the other groups (p<0.05). The cell number of the inner cell mass was higher in AS/V-T/non-AH and AS/V-T/cMAH groups than those of others (p<0.05). In the control group, the number of trophectoderm and the total cell number were higher than in the AS-AH group (p<0.05). CONCLUSION: The above results suggest that AS and AH in vitrification of expanded blastocysts lead to the more efficient formation of hatched blastocysts in mice.
Subject(s)
Animals , Female , Humans , Mice , Pregnancy , Blastocyst , Cell Count , Chorionic Gonadotropin , Embryo Transfer , Embryonic Development , Embryonic Structures , Fluorescence , Flushing , Gonadotropins , Herpes Zoster , Oviducts , Superovulation , VitrificationABSTRACT
OBJECTIVE: The aim of this study was to compare the survival and developmental rate of two vitrification solutions for the vitrification of mouse expanded blastocysts. METHODS: Mouse embryos were obtained at 2 cell stage and cultured to expanded blastocyst stage in Human Tubal Fluid (HTF) medium supplemented with 10% serum substitute supplement (SSS). The vitrification solutions used were EFS40 and VS. EFS40 consisted of 40% ethylene glycol, 18% ficoll, and 0.5 M sucrose while VS consisted of 20% ethylene glycol, 20% DMSO, and 10% 1,3-butanediol diluted in Dulbecco's phosphate-buffered saline (DPBS) medium supplemented with 10% calf serum (CS). Toxicity was tested by exposing expanded blastocysts to vitrification solution. The vitrification procedure used for EFS40 was performed in three steps, after which they were warmed in 5 steps with 0.5 M sucrose. VS was performed in two steps, after which they were warmed with 1.0 M trehalose. Recovery, survival and hatching rate per expanded blastocysts recovered were compared between two groups. RESULTS: In toxicity test, survival and hatching rate of EFS40 group were 95% and 100%, respectively. In contrast, survival and hatching rate of VS group were 100% and 87.5%, respectively. After vitrification and warming in solution, recovery rate for EFS40 group was 73.7% whereas recovery rate for VS group was 66.5%. After 24 h culture, survival and hatching rate were 80.5% and 20.7% for EFS40 and 66% and 0% for VS group, respectively. After 48 h culture, survival and hatching rate were 69% and 33.3% for EFS40 and 58.3% and 1.9% for VS group, respectively. Survival and hatching rate in EFS40 group were significantly higher than those found in VS group. CONCLUSION: The EFS40 solution was better than VS solution for vitrification of mouse expanded blastocysts.
Subject(s)
Animals , Humans , Mice , Blastocyst , Dimethyl Sulfoxide , Embryonic Structures , Ethylene Glycol , Ficoll , Sucrose , Toxicity Tests , Trehalose , VitrificationABSTRACT
No abstract available.