Background: The aim of the study was 2-fold: first, to investigate couples' reasons for not using cryopreserved embryos within the maximum storage period; second, to study their attitudes towards potential embryo donation for specific purposes.
Methods: A questionnaire was sent to 284 IVF/ICSI couples who experienced destruction of their cryopreserved embryos (n=1180) because the cryopreservation period exceeded the Danish legislative limit of 24 months.
Results: Seventy-four per cent of the couples responded. The main reasons for not utilizing surplus embryos was 'successful delivery' (85%), 'consider family completed' (61%) and 'too short legislative limit for cryopreservation' (59%). Sixty per cent of the couples agreed to the concept of donation of cryopreserved embryos for infertility research, 57% responded affirmatively to donation for stem cell research and 49% for stem cell treatment, but only 29% agreed to the concept of donation to infertile couples. Multiple logistic regression analysis showed that delivery of a child after IVF treatment (OR 3.8, 95% CI 1.4-10.2) and female age <35 years (OR 2.2, 95% CI 1.3-6.0) were predictive of agreement to the idea of donation for stem cell research and stem cell treatment respectively; however, male age, duration of infertility, mode of conception (IVF or ICSI) and having IVF children were not significant predictors. The following predictive variables were entered into the analysis: female and male age, duration of infertility, IVF versus ICSI, donor semen and +/- IVF children.
Conclusions: This study shows that 23% of all couples having cryopreserved embryos do not utilize them for further treatment within the legislative storage period of 2 years. A major reason is successful delivery. More than half of these patients agreed to the concept of donation of surplus outdated embryos for research, whereas less than one-third agreed to donation to other infertile couples. Based on these figures, an alternative utilization of surplus embryos for stem cell research would require a 100-fold larger pool of available embryos to provide a realistic basis for this purpose.