Low as well as high serum P4 levels in the early and mid-luteal phase reduce the chance of a live birth following IVF treatment with fresh embryo transfer: Where is the evidence?

Thomsen et al. (2018) recently published a prospective, observational multicentric study evaluating the prognostic value of early and mid-luteal serum progesterone concentration for the achievement of live birth after fresh embryo transfer. Based on data from 602 IVF cycles, the authors conclude that ‘low as well as high serum P4 levels in the early and mid-luteal phase reduce the chance of a live birth following IVF treatment with fresh embryo transfer’. This is an important finding that could potentially change patient management