Interaction between embryo transfer timing (D3/D4) and duration of progesterone exposure (P3/P4) on live birth rate in hormone replacement therapy cycles of frozen embryo transfer.

ABSTRACT:

Objective

In hormone replacement therapy (HRT) cycles of frozen embryo transfer (FET), progesterone-induced endometrial transformation is critical to clinical outcomes. This study aimed to evaluate the interactive impact of the extent of progesterone exposure and the timing of embryo transfer on live birth outcomes.

Methods

This study retrospectively reviewed 3,381 infertile individuals from June 2013 to June 2024. Participants were stratified into four categories based on the number of days of progesterone exposure (P) and embryo developmental stage at transfer (D): P3-D3 group, P3-D4 group, P4-D3 group, and P4-D4 group.

Results

Analysis showed comparable baseline characteristics among all groups, with no significant variation. When progesterone exposure duration was

SUBMITTER: Wang Y 

PROVIDER: S-EPMC12522355 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature