Pregnancy after the replacement of a frozen-thawed embryo with less than 50% intact blastomeres

Early embryo freezing with saccharose and propanediol gives a survival rate of 62% of the embryos if 4 cell embryos with only one intact blastomere after thawing are included. The first pregnancy achieved with such an embryo is reported as well as preliminary results obtained in our IVF programme using the French method.