Optimization of a novel nylon mesh container for human embryo ultrarapid vitrification.
OBJECTIVE
To evaluate the efficacy of a nylon mesh container in vitrification of human embryos and to determine the optimal osmotic pressure of the initial thawing solution.


METHODS
Retrospective analysis.


METHODS
National Center for Child Health and Development, Tokyo, Japan.


METHODS
Infertile patients undergoing either in vitro fertilization or intracytoplasmic sperm injection in our hospital.


METHODS
Embryos, at the cleavage stage, were cryopreserved using the vitrification method in either a plastic straw or a nylon mesh container. The embryos were thawed using an initial osmotic pressure of either 0.5 M or 1.0 M sucrose with subsequent step-wise dilution. After thawing, the embryos were transferred to the uterus.


METHODS
Survival rate of blastomeres, embryo survival rate, implantation, and pregnancy rates, cancellation rate because of embryo damage.


RESULTS
Use of nylon mesh and the 1.0 M sucrose thawing solution significantly improved blastomere survival rate (98.0 +/- 1.0%, mean +/- SEM), pregnancy rate (41.0%) and implantation rate (32.3%).


CONCLUSIONS
Vitrification using a nylon mesh container and subsequent thawing in a 1.0 M sucrose solution is an easy and inexpensive method that improves the reliability of embryo cryopreservation of embryos without adverse effects on clinical outcomes.
Nakashima
Akira
A
Division of Reproductive Medicine, Department of Perinatal and Maternal Care, National Center for Child Health and Development, Tokyo 157-8535, Japan. nakashima_akira@kurume-u.ac.jp
Ino
Nao
N
Kusumi
Maki
M
Ohgi
Shirei
S
Ito
Megumu
M
Horikawa
Takashi
T
Nakagawa
Koji
K
Saito
Takakazu
T
Kamura
Toshiharu
T
Saito
Hidekazu
H
D000328:Adult; D002138:Calibration; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D003451:Cryoprotective Agents / Q000494:pharmacology; D010064:Embryo Implantation / Q000187:drug effects / Q000502:physiology; D004622:Embryo, Mammalian; D005260:Female; D005328:Fetal Viability / Q000187:drug effects; D006801:Humans; D008297:Male; D008954:Models, Biological; D009757:Nylons / Q000494:pharmacology; D010969:Plastics / Q000494:pharmacology; D011247:Pregnancy; D018873:Pregnancy Rate; D019064:Product Packaging; D012189:Retrospective Studies; D013526:Surgical Mesh; D013997:Time Factors
D003451:Cryoprotective Agents; D009757:Nylons; D010969:Plastics