Systemic progesterone correction in cryotransfer cycles: clinical stratification and individualized approach

Progesterone is a key systemic hormone in ART programs, and monitoring its levels is especially important in cryopreservation cycles during cyclic hormone therapy, where deficiency can negatively impact pregnancy outcomes. In such cycles, monitoring serum progesterone allows for personalized support, while water-soluble subcutaneous progesterone provides reliable systemic correction in cases of suboptimal levels or intolerance to vaginal forms. In cases of maintained ovulatory cycles, preference may be given to natural and modified natural protocols, while the choice of preemptive systemic support, the timing of dose reduction during pregnancy, and the strategy for at-risk patients require an individualized approach and further study. The objective of this review is to determine optimal approaches to luteal support and personalized progesterone use in embryo cryopreservation programs, depending on the clinical situation and serum progesterone levels.