Evidence mapPaperPMID 41476607Full record

ArticleFrontiers in cell and developmental biology2025

Low-dose letrozole-HMG regimen reverses letrozole-induced endometrial impairment and improves frozen embryo transfer outcomes.

Zhonglin Xiao, Feng Wang, Yali Yang, Tianxia Xiao, Jie Chen, Mengxia Li, Haizhen Liao, Chiawei Chu, Xiujun Fan, Jian V Zhang

Abstract read
In one paragraph

Article in Frontiers in cell and developmental biology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Zhonglin Xiao *Faculty of Data Science, City University of Macau, Macau, China.
Feng Wang *Reproductive Medicine Centre, Shenzhen Hengsheng Hospital, Shenzhen, China.
Yali Yang *Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Tianxia XiaoShenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Jie ChenShenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Mengxia LiShenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Haizhen LiaoReproductive Center of Shenzhen Armed Police Hospital, Shenzhen, China.
Chiawei ChuFaculty of Data Science, City University of Macau, Macau, China.
Xiujun FanShenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
Jian V ZhangShenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Letrozole monotherapy, while effective for ovulation induction, may compromise endometrial receptivity in frozen embryo transfer (FET) cycles due to estrogen suppression. This study aimed to compare the FET outcomes and analyze the molecular mechanisms of endometrial receptivity among low-dose letrozole plus HMG (LeH) with letrozole monotherapy (Le) and natural cycles (NC). Methods: This retrospective cohort study included 5,673 infertile patients undergoing FET with one of the following protocols: LeH (n = 2,997), Le (n = 1,762), or NC (n = 914). Endometrial receptivity was assessed via serum hormone assays, scanning electron microscopy (SEM) of pinopodes on post-ovulation days 3 (D3; pre-FET) and 5 (D5; estimated implantation window), and proteomic analyses of endometrial tissue, uterine fluid, and serum on D3. Results: Clinical outcomes revealed that the LeH group had significantly higher implantation, clinical pregnancy and live birth rates compared to the Le and NC groups, especially among older women. Notably, the Le group was associated with thinner endometrium, lower estradiol levels, reduced vascularization flow index (VFI), and a lower proportion of receptive-phase endometria (28% vs. 60% in NC). In contrast, the LeH group maintained normal endometrial parameters, and resulted in a high proportion of fully developed pinopodes (84%). Proteomic profiling revealed that the Le group adversely affected processes related to cell adhesion and inflammatory regulation, while the LeH group reversed these alterations. It activated pathways important for embryo implantation and promoted an anti-inflammatory environment. Discussion: These results suggest that the LeH regimen may mitigate letrozole-induced endometrial impairment and enhances FET outcomes through structural, molecular, and immunological mechanisms, offering a promising approach for optimized endometrial preparation.

Indexed as

endometrial receptivityfrozen embryo transferhuman menopausalgonadotropinimplantationinfertilityletrozolepinopodeproteomics

Identifiers

PMID41476607
PMCPMC12748246

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.