Reproductive healthLecture
Personalized luteal phase support
Luteal phase support based on serum progesterone monitoring: why standard vaginal therapy fails to reach the protective level in a subset of patients on the hormone replacement cycle, how to define the threshold value on transfer day, and when a change in the route of administration is indicated. Arguments for moving toward natural and modified natural FET cycles.
Audio: MultiSubtitles: EN · UA · RU27 min
Elena Labarta
MD, PhD
Gynecologist, reproductive surgeon and researcher at IVI RMA Valencia, specializing in human reproduction and assisted reproductive techniques since 2005. Her research focuses on serum progesterone in embryo transfer cycles and luteal phase management. Associate Professor of Master's programmes in assisted reproduction at the University of Valencia and author of more than 50 scientific papers.
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Luteal phase support in FET cycles has long been treated as a one-size-fits-all protocol. A growing body of prospective data shows that this approach leaves a substantial subset of patients below the protective serum progesterone threshold — and that better monitoring, multi-route rescue and a gradual shift toward natural-cycle FET could measurably improve outcomes.
Serum progesterone as a clinical lever
In hormone replacement therapy (HRT) FET cycles, the absence of a corpus luteum means that achieved serum progesterone depends entirely on exogenous administration. Multiple prospective studies show that approximately one in three patients on standard vaginal progesterone falls below the protective threshold of 9–10 ng/mL on transfer day — with a measurable drop in ongoing pregnancy rates.
