Towards a better understanding of preimplantation genetic screening and cumulative reproductive outcome: transfer strategy, diagnostic accuracy and cost-effectiveness

A decision model was constructed to compare genetic testing and not testing, for the transfer of all suitable embryos, one at a time, from a cycle with up to ten embryos, until a first live birth was achieved or there were no more embryos available (a full cycle). Two strategies were investigated: (i) a fresh transfer with subsequent serial warmed cryopreserved embryo replacement, and (ii) freeze-all prior to serial embryo replacement. Sensitivity analyses were performed to assess the effect of embryo warming survival and diagnostic accuracy on cumulative rates. Cost-effectiveness was assessed using the incremental cost-effectiveness ratio for a live birth event, and a clinical miscarriage avoided. Reproductive outcome probabilities were obtained from published prospective non-selection studies, and costs from websites and publications. Given 100% embryo warming survival and no false abnormal genetic test results, the live birth rate for a full cycle was the same with and without testing for both transfer strategies. Compared to not testing, it was theoretically possible for testing to be favoured for live birth only for the fresh and frozen transfer strategy, where more than one embryo was available, and dependent on the efficiency of warming survival and the positive predictive value of the test; however, this was unlikely to be cost-effective from a society perspective without a substantial reduction in genetic testing costs. For both transfer strategies, when more than one embryo was available, testing was more likely to achieve a live birth event following the first attempt with fewer attempts required overall. Testing was likely to be effective to avoid a clinical miscarriage but also to be expensive from a society perspective compared to the cost of dilation and curettage.