Edwards' syndrome after the replacement of cryopreserved-thawed embryos. A case of Edwards' syndrome after the replacement of frozen-thawed embryos is reported. The presence of cardiac abnormalities and limb deformities raised the suspicion of chromosomal abnormality. The diagnosis of trisomy 18 was made by cytogenetic analysis of fetal blood from the umbilical vein. The chromosomal nondisjunction might have been spontaneous or because of freezing and thawing. If it occurred as a result of freezing and thawing, it is more likely that this was at the first cleavage division rather than the second meiotic division because the embryos were frozen at the late pronuclear stage. Unfortunately, there were no karyotypic markers in the couple's chromosomes to time the nondisjunction. The wisdom of using donor oocytes in an ovum donation program from patients with long-standing infertility is questioned. 