Ongoing pregnancies after vitrification of human oocytes using a combined solution of ethylene glycol and dimethyl sulfoxide

Fertil Steril. 2006 Oct;86(4):997-1000. doi: 10.1016/j.fertnstert.2006.02.117. Epub 2006 Sep 11.


Objective: To evaluate a vitrification solution using a mixture of two cryprotectant agents, dimethyl sulfoxide and ethylyne glycol plus sucrose, on the survival of human oocytes.

Design: Clinical study of cryopreservation of human metaphase II (MII) oocytes by vitrification.

Setting: University-affiliated IVF center.

Patient(s): Infertile couples who agreed to have their surplus oocytes vitrified during the fresh IVF cycle.

Intervention(s): Vitrification of surplus oocytes subsequently used in the next cycle and assisted fertilization by intracytoplasmic sperm injection.

Main outcome measure(s): Morphologic survival and normal fertilization, embryo development, and clinical outcome.

Result(s): A total of 53 surplus MII oocytes from 6 patients were vitrified, of which 24 were thawed, resulting in 18 which survived morphologically (75%). Following insemination, 14 of the 18 surviving eggs were fertilized (77.7%). All zygotes developed into viable embryos that were replaced into each patient's uterus, resulting in two healthy pregnancies: one singleton and one twin. The pregnancies were ongoing.

Conclusion(s): Cryopreservation of human MII oocytes by vitrification appears to be a promising procedure, though to assure optimal effectiveness of this protocol further studies should be undertaken.

MeSH terms

  • Adult
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cryopreservation / methods*
  • Cryoprotective Agents / administration & dosage
  • Dimethyl Sulfoxide / administration & dosage*
  • Drug Combinations
  • Ethylene Glycol / administration & dosage*
  • Female
  • Fertilization in Vitro / methods*
  • Humans
  • Infertility / therapy*
  • Oocytes / cytology
  • Oocytes / drug effects*
  • Oocytes / transplantation*
  • Pregnancy
  • Pregnancy Outcome
  • Treatment Outcome


  • Cryoprotective Agents
  • Drug Combinations
  • Ethylene Glycol
  • Dimethyl Sulfoxide