Cryopreservation of human failed maturation oocytes shows that vitrification gives superior outcomes to slow cooling.
This study investigated whether failed maturation oocytes could be used to evaluate different cryopreservation procedures. A total of 289 failed maturation oocytes (GV and MI stages), obtained from 169 patients undergoing IVF treatment (mean age 33.84±5.0) were divided into two different slow-cooling groups (1.5 mol/l 1,2-propanediol+0.2 mol/l sucrose in either NaCl (group A) or choline chloride (ChCl) (group B) based cryopreservation solutions) and one vitrification group (15% ethylene glycol+15% dimethyl sulphoxide). Survival rate, in vitro maturation (IVM) rate, fertilization and developmental rate of cryopreserved oocytes were assessed. Regardless of the stage at which cryopreservation was performed (GV+MI), the slow cooling with ChCl based medium always gave significantly lower survival rate than the slow cooling in NaCl based medium (p=0.01) and vitrification (p<0.001). An extended study also showed statistically reduced survival rate between slow-cooling NaCl based medium and vitrification (p<0.05). Global results of in vitro maturation and fertilization showed worse results between both slow-cooling NaCl and ChCl based media versus vitrification. In conclusion, for oocytes that had failed to mature, vitrification gave better survival, maturation, fertilization and also cleavage rates than the slow-cooling protocols. Four cells embryos were obtained only from vitrified in vitro matured MI oocytes.
Fasano
G
G
Laboratory for Human Reproduction Research, Faculty of Medicine, Campus Erasme, Université Libre de Bruxelles (ULB), Belgium. Giovanna.Fasano@erasme.ulb.ac.be
Vannin
A S
AS
Biramane
J
J
Delbaere
A
A
Englert
Y
Y
D000328:Adult; D002470:Cell Survival; D002794:Choline / Q000494:pharmacology; D015925:Cryopreservation / Q000379:methods; D005260:Female; D006801:Humans; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology; D058989:Vitrification
D012965:Sodium Chloride; D002794:Choline