Pregnancy after human oocyte cryopreservation.
The first successful attempt at deep freezing and thawing of the human oocyte is reported. A twin pregnancy was achieved after insemination and replacement in utero. The procedure involved reduction in size of the oocyte/cumulus-oophorus complex, the addition of the cryoprotectant dimethyl sulphoxide as a one-step procedure, slow cooling between -7 degrees C and -36 degrees C after ice nucleation, and rapid freezing to -196 degrees C before storage in liquid nitrogen. Thawing was achieved rapidly by warming in a 37 degrees C water-bath, followed by dilution of dimethyl sulphoxide as a single step. 80% of forty oocytes showed morphological survival after freezing and thawing. Thirty of these were inseminated; 83% retained their capacity to be fertilised, and 60% proceeded to cleavage division.
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D000818:Animals; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004624:Embryo Transfer; D005260:Female; D005615:Freezing; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000254:growth & development / Q000502:physiology*; D011247:Pregnancy; D013997:Time Factors; D014021:Tissue Preservation / Q000379:methods*
D004121:Dimethyl Sulfoxide