The role of Progesterone administration during the frozen-thawed embryo transfers has been deeply debated during the last ESHRE meeting held in Vienna this month. On one hand, Elena Labarta from IVIRMA-Valencia has shown the results of studies demonstrating that low levels of serum progesterone in the day of embryo transfer are associated with low ongoing pregnancy rates. At the same time, the author has revealed that it is possible to “rescue” a bad cycle (in term of insufficient progesterone levels) by adding the hormone subcutaneously the day of embryo transfer and onwards.
Georg Griesinger has underlined the fact that the role of progesterone does not limit to endometrial receptivity. Indeed, immunomodulation and myometrial quiescence are also affected by progesterone levels.
Definitely, once ovarian stimulation has been thoroughly assessed and euploid embryo (the seed) transfer has become the gold standard in assisted reproduction, endometrial preparation (the ground) and adequate progesterone administration (both, in term of doses and via of administration) play the starring role in assisted reproduction.