Cumulative Live Birth Rate (CLBR) After a Complete IVF Cycle: a Single Center

Traditionally, studies about In Vitro Fertilization (IVF) examine and report the 'per cycle' and 'per embryo transfer procedure' probability of pregnancy and delivery .Thus, each IVF cycle is considered as a unique entity even if several embryo transfers (ET) have been performed after a single ovarian stimulation.

Thanks to the latest technological refinements, in recent years the number of thawed frozen ETs has greatly increased and has become an essential feature of IVF procedures .This practice has been encouraged by the strategy of preferring single ET for reducing multiple pregnancy and preventing ovarian hyperstimulation in high risk women.

Moreover, at first infertility counseling patients usually want to know which is their possibility to have a live birth child with ART treatment, after the first stimulation cycle, also involving the chances after frozen ET or frozen oocytes injection.

Live birth rate (LBR) after a single fresh or frozen ET appears, at present time, to be an insufficient parameter for a realistic evaluation of the efficacy of an IVF program.

We need to identify a new parameter for the evaluation of the success rate of IVF techniques which should incorporate outcomes associated with a single controlled ovarian stimulation cycle. Specifically, Cumulative live birth rate (CLBR) has been suggested as a suitable way for reporting success of IVF program : it implies capturing the totality of live birth episodes following successive treatments.