Six year follow-up of cryopreserved human embryos.
In 1987, we became aware of the importance of remaining in contact with couples whose embryos had been cryopreserved for > 1 year. As a result, a questionnaire was designed to follow the fate of these embryos. Of 407 couples with cryopreserved embryos, 262 couples opted to use them within 1 year with the intention of fulfilling a parental plan. The remaining 145 couples were questioned by six successive questionnaires sent out between 1987 and 1992. By the end of the study, 336 of the 407 couples (82.5%) had chosen to utilize their embryos in a parental plan. In most cases, the maximum delay of response (5 years according to the Council of State) was respected. The remaining 71 couples (17.5%) either abandoned the parental plan or had not given any information by the end of the study. Initially, anonymous donation to another couple was chosen in preference to destroying the surplus embryos (32 versus 18 couples, P < 0.05). Latterly, however, these differences have balanced out (24 versus 28, not significant). Only those couples who initially opted to donate embryos to another couple changed their attitude in later years. In the long run, 62 couples decided not to pursue their parental plan; of these, 24 couples chose to make a gift to another couple, 28 couples opted for destruction, and 10 chose to make a gift to research. Nine couples (out of 71) declined to make a decision, but they had all achieved a pregnancy during an in-vitro fertilization (IVF) attempt. Three of these were lost to follow-up, i.e. 0.7% of all couples benefiting from the freezing technique.