Aseptic vitrification of human germinal vesicle oocytes using dimethyl sulfoxide as a cryoprotectant.
OBJECTIVE
To evaluate the viability of vitrified human germinal vesicle (GV)-oocytes to mature to metaphase II (MII) stage after "rapid" cooling directly in liquid nitrogen in comparison with "slow" cooling in a closed 0.5-mL straw (aseptic system), with or without dimethyl sulfoxide (DMSO) in vitrification solution. The possibility of avoiding parthenogenesis of the oocytes after vitrification using DMSO was investigated.


METHODS
In vitro maturation after vitrification.


METHODS
Assisted reproduction centers.


METHODS
Patients undergoing standard superovulation treatment and having GV-oocytes after follicular puncture.


METHODS
The GV-oocytes were vitrified with long/short exposure to DMSO using slow or rapid cooling, then warmed and matured in vitro.


METHODS
Maturation after warming.


RESULTS
Oocyte development up to MII stage after vitrification with DMSO was 71% in the group with "rapid" cooling, and in groups with "slow" cooling, 68% and 72% for long and short exposure to DMSO, respectively. The maturation rate of GV-oocytes after slow cooling without DMSO was 51%. In the vitrification with long-term contact of oocytes with DMSO group, a high rate of parthenogenesis was observed. When vitrification with short-term contact of oocytes with DMSO at room temperature was used, no parthenogenesis was observed.


CONCLUSIONS
Cryopreservation of human GV-oocytes in open-pulled straws OPS) using an aseptic slow cooling method gives high maturation rates but only in combination with DMSO. To avoid spontaneous parthenogenesis, the exposure to DMSO must occur for a reduced time and at room temperature.
Isachenko
Vladimir
V
Department of Gynecological Endocrinology and Reproductive Medicine, University of Bonn, Bonn, Germany. vovaisachenko@yahoo.com
Montag
Markus
M
Isachenko
Evgenia
E
Dessole
Salvatore
S
Nawroth
Frank
F
van der Ven
Hans
H
D001207:Asepsis; D002470:Cell Survival / Q000187:drug effects; D016922:Cellular Senescence / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008677:Metaphase; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D010312:Parthenogenesis / Q000187:drug effects; D013997:Time Factors
D003451:Cryoprotective Agents; D004121:Dimethyl Sulfoxide