Timing of progesterone exposure for programmed frozen transfer of day 6 blastocysts: a systematic review and narrative synthesis.
Reprod Biomed OnlineJun 14, 2026 (epub)
Clinical ResearchObstetrics & Gynecology
Karina Silveira Leite Tafner, Newton Eduardo Busso
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In 30 seconds
This systematic review evaluated the impact of progesterone exposure duration on reproductive outcomes in programmed frozen transfer of day 6 blastocysts. The analysis included randomized and observational studies, revealing that live birth rates were comparable after 6 or 7 days of progesterone exposure, with one large subgroup analysis indicating a significant advantage for 7 days. The findings suggest that both durations are viable options.
Key findings
- Live birth rates after D6 blastocyst transfer were comparable for 6 and 7 days of progesterone exposure.
- One large subgroup analysis showed a significant live birth advantage for 7 days of progesterone exposure.
- 7 days of progesterone exposure was associated with a significantly lower miscarriage rate than 6 days in two studies.
Why it matters
Understanding the optimal duration of progesterone exposure can help clinicians improve reproductive outcomes in assisted reproduction, particularly for patients undergoing frozen embryo transfer.