Evidence map›Paper›PMID 40956336›Full record

SynthesisArchives of gynecology and obstetrics2025

How embryo retention affects assisted reproductive technology outcomes: a systematic review and meta-analysis.

Arezoo Maleki-Hajiagha, Rana Karimi, Neda Emami, Fardin Amidi

Abstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in Archives of gynecology and obstetrics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Review
4 · The record

Corrections and comments

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

4 authors.

Arezoo Maleki-HajiaghaDepartment of Anatomy, School of Medicine, Tehran University of Medical Sciences, Pour Sina St., Ghods St., Keshavarz Blvd., Tehran, Iran.
Rana KarimiDepartment of Obstetrics and Gynecology, Arash Women's Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Neda EmamiDepartment of Obstetrics and Gynecology, Arash Women's Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Fardin AmidiDepartment of Anatomy, School of Medicine, Tehran University of Medical Sciences, Pour Sina St., Ghods St., Keshavarz Blvd., Tehran, Iran. Famidi@tums.ac.ir.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRetransferring retained embryos during the embryo transfer (ET) procedure has raised concerns about its adverse effects on assisted reproductive technology (ART) outcomes. Technical challenges associated with embryo retention (ER) may compromise implantation success and lead to increased complications.

objectiveThis systematic review and meta-analysis aimed to evaluate the impact of retransferring retained embryos on key ART outcomes, including clinical pregnancy rate (CPR), biochemical pregnancy rate (BPR), ectopic pregnancy rate (EP), miscarriage rate (MR), and live birth rate (LBR).

methodsWe conducted a systematic search in PubMed, Scopus, and Cochrane databases from inception to April 11, 2025. ART outcomes were extracted and pooled Mantel-Haenszel odds ratios (OR) with 95% confidence intervals (CI) were calculated under both fixed- and random-effects models. Subgroup analyses were performed based on study design (matched versus non-matched retrospective cohorts) and ET technique (afterload versus direct). Sensitivity analyses were conducted by excluding studies with high or very high risk of bias, as determined by the ROBINS-E tool.

resultsThe overall analysis demonstrated that retransferring retained embryos was associated with a significant reduction in CPR (OR ≈ 0.75, 95% CI: 0.64-0.89, p < 0.001) and LBR, while substantially increasing the risk of EP (OR ≈ 2.36, p = 0.036). Subgroup analysis showed that studies with matched designs and those using the afterload ET technique exhibited more pronounced negative outcomes. Sensitivity analyses confirmed the robustness of the primary findings.

conclusionER negatively impacts ART success, lowering clinical pregnancy and live birth rates and elevating the risk of ectopic pregnancy. These findings highlight the critical need to refine ET protocols and further investigate the biological mechanisms underlying ER. Future well-designed, prospective studies with standardized methodologies are warranted to optimize ER management and improve clinical outcomes.

Indexed as

Embryo TransferReproductive Techniques, AssistedAbortion, SpontaneousEmbryo ImplantationFemaleHumansLive BirthPregnancyPregnancy, EctopicPregnancy RateAssisted reproductive technologyComplicated embryo transferEmbryo retentionEmbryo transfer catheterRetained embryo

Identifiers

PMID40956336
PMCPMC12589232

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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 OpenQuestion graph.