The survival and development rates in mouse embryo cryopreservation.
A research of mouse embryo cryopreservation was carried out in our department in order to establish the clinical service of human embryo cryopreservation. Mouse embryos were stored in glass vials using 1.5M propanediol (PROH) or 1.5M dimethyl sulfoxide (DMSO) as cryoprotectants and we used a modified four-step equilibration method to minimize osmolarity shock. We divided the 1490 embryos into two phases and compared phase 1 to phase 2. After achieving more sophisticated handling techniques and more accurate timing of each procedure, the survival rate (25% vs 59.8%) and stage advancing rate (5.2% vs 33.5%) were all improved in phase 2. The proportion of frozen embryos developing to hatched blastocysts was significantly increased from 14.5% to 56.7% in the 4-cell embryo groups compared to the 2-cell embryo groups. Two kinds of cryoprotectants were used in the 4-cell embryos and the results showed no difference in the post thaw survival rate but a better blastocystic development in the propanediol group (64.0% vs 41.5%). The results obtained from this study have encouraged us to initiate a major clinical trial of the technique in our IVF programs. Two pregnancies have been established upon the transfer of cryopreserved embryo and two normal healthy infants have already delivered at our hospital.
Lee
J D
JD
Department of Obstetrics & Gynecology, Chang Gung Memorial Hospital, Taipei, Taiwan, R.O.C.
Chang
M Y
MY
Chen
F P
FP
Soong
Y K
YK
D000818:Animals; D015925:Cryopreservation; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D051379:Mice; D011247:Pregnancy