OPINION Is meaningful reporting of national IVF outcome data possible?

The traditional use of live birth per IVF cycle started as the sole indicator of success can be potentially misleading. Different policies regarding reporting IVF cycles started, variations in the number of embryos transferred and associated multiple births have a profound effect on success, such that results from clinics or countries with similar expertise may appear significantly different. To account for these differences, we recommend the use of live birth per embryo—calculated as the number live birth events per 100 embryos transferred—as an outcome measure. This method of reporting can correct for under reported cycles started, adjust for differences in embryo transfer policies and pro-vides an objective and reproducible international benchmark. Combining live birth outcomes from fresh and frozen cycles in the same report-ing period per oocyte collection is also recommended. These data should be published as a range related to the national average without a mean or central point. Furthermore, for proper interpretation of results, it would be helpful if the policies regarding patient inclusion and cycle cancellation at all clinics are published