Impact of endometrial thickness on reproductive outcome in fresh and frozen–thawed embryo transfer: systematic review and meta‐analysis
Notice bibliographique
Résumé
ABSTRACT Objective To evaluate the impact of endometrial thickness on the reproductive outcomes of embryo transfer (ET) treatments using both cut‐off‐based meta‐analysis and meta‐analysis of proportions. Methods This was a systematic review and meta‐analysis of comparative studies (randomized controlled trials, cohort studies, case–control studies) and descriptive studies (cross‐sectional studies, case series) published in English, French, German, Italian or Spanish and analyzing the impact of endometrial thickness on the rates of embryo implantation, clinical pregnancy, live birth, miscarriage and/or ectopic pregnancy in fresh and/or frozen–thawed ET cycles. Live‐birth rate was defined as the primary outcome. The literature search was conducted in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov , Web of Science and ÍnDICEs‐CSIC, from inception of each database until 1 September 2024. The risk of bias was assessed using the Newcastle–Ottawa scale for analytical studies and the Joanna Briggs Institute tool for descriptive studies. Pooled effects were estimated as odds ratios (OR) or risk differences obtained from a random‐effects model, with 95% CIs. Linear meta‐regression was used to assess the relationship between risk difference and endometrial thickness cut‐off. Meta‐analysis of proportions was performed as a secondary analysis, comparing outcome rates between 2‐mm intervals of endometrial thickness and a reference category (≥ 6 to < 8 mm). Results A total of 67 studies were included, of which 22 were cohort studies and 45 were descriptive. In fresh ET cycles, the live‐birth rate was higher in patients with a thicker endometrium across cut‐offs from ≥ 5 mm (OR, 5.66 (95% CI, 1.10–28.98)) to ≥ 15 mm (OR, 1.49 (95% CI, 1.26–1.77)). Effect size decreased linearly as the cut‐off increased ( P < 0.0001; R 2 = 61.5%). Meta‐analysis of proportions found significant differences in live‐birth rate when the reference category (≥ 6 to < 8 mm) (0.26 (95% CI, 0.22–0.30); I 2 = 94.3%) was compared to the groups with endometrial thickness of ≥ 4 to < 6 mm (0.17 (95% CI, 0.14–0.20); I 2 = 0%), ≥ 10 to < 12 mm (0.35 (95% CI, 0.28–0.42); I 2 = 99.2%), ≥ 12 to < 14 mm (0.43 (95% CI, 0.33–0.53); I 2 = 99.5%) and ≥ 14 to < 16 mm (0.39 (95% CI, 0.27–0.51); I 2 = 99.2%). In frozen–thawed ET cycles, thicker endometrium was associated with a higher live‐birth rate for cut‐offs between ≥ 5 mm (OR, 2.65 (95% CI, 1.23–5.72); I 2 = 0%) and ≥ 8 mm (OR, 1.17 (95% CI, 1.10–1.24); I 2 = 13%). A linear relationship between endometrial thickness and effect size was observed for this analysis ( P < 0.0001; R 2 = 73.8%). In fresh ET cycles, endometrial thickness was correlated positively with the rates of clinical pregnancy and embryo implantation, inversely with miscarriage rate and showed no correlation with ectopic pregnancy. In frozen–thawed ET cycles, thicker endometrium was correlated positively with the rate of clinical pregnancy and inversely with that of miscarriage. Evidence quality was rated as very low in 70% of assessments because of bias and inconsistency. Conclusions Endometrial thickness is associated with reproductive outcomes, but demonstrates a gradient of effectiveness as a prognostic indicator, rather than offering a critical threshold below which ET should be avoided. ET scheduling should consider endometrial thickness alongside other prognostic factors. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,003 | 0,067 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,013 | 0,001 |
| Bibliométrie | 0,003 | 0,004 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».