ReviewReproductive medicine and biology2021
Meta-analysis of the embryo freezing transfer interval.
Review in Reproductive medicine and biology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05215119 (Comparison of Immediate With Delayed Natural Cycle Frozen Embryo Transfers From Freeze-all-IVF Cycles), which is not on this map. Cited by 7 papers, 1 of them a synthesis that pooled 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.
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.
Comparison of Immediate With Delayed Natural Cycle Frozen Embryo Transfers From Freeze-all-IVF Cycles: a Randomized Control Trial of First Frozen Embryo Transfers
Who cites it
7 citing papers in PubMed, 1 synthesis or guideline pooled it, 15 citations in OpenAlex.
- Polycystic ovarian syndrome and miscarriage in IVF: systematic revision of the literature and meta-analysis.Archives of gynecology and obstetrics · 2023Pooled it
- Impact of embryo storage time after vitrification on pregnancy and implantation rates.JBRA assisted reproduction · 2025Article
- microRNA-based signatures obtained from endometrial fluid identify implantative endometrium.Human reproduction (Oxford, England) · 2022Article
- It is not worth postponing frozen embryo transfers after oocyte pickup: A retrospective cohort study based on propensity score matching.Frontiers in endocrinology · 2022Article
- Effect of interval between oocyte retrieval and resuscitation embryo transfer on pregnancy outcomes.Frontiers in medicine · 2022Article
- Meta-analysis of the embryo freezing transfer interval.Reproductive medicine and biology · 2021Review
- Aspiration of excess follicles before intrauterine insemination in high response cycles.Reproductive medicine and biologyArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe decision of whether frozen embryo transfer (FET) should be performed in the cycle immediately after OPU or at least one cycle later is controversial. FET could improve pregnancy rates in IVF; however, how much time is needed for the endometrium to return to optimal receptivity after ovarian stimulation is not known.
methodsElectronic search in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials to identify studies providing data on the influence of the interval between embryo freezing (or OPU) and FET in FET cycles published between January 1, 2007, and February 1, 2020. MAIN
findingsData analyzed indicated that in the immediate FET cycles, there was a trend to an increased biochemical pregnancy rate (RR = 1.08; CI = 1.00-1.18), whereas the clinical pregnancy rate was somewhat higher, but without reaching statistical significance (RR = 1.07; CI = 0.99-1.15). The live birth rate was similar in the two groups (RR = 1.05; CI = 0.95-1.15), as was the implantation rate (RR = 0.98; CI = 0.83-1.16). Stratifying by embryo stage or FET type (freeze-all or FET after failed fresh transfer) showed no differences.
conclusionSystematically delaying FET does not offer benefits to IVF outcomes. In addition, immediate transfer is associated with a nonsignificant trend to better clinical pregnancy rate and it also avoids the psychological effects of prolonging the stress on prospective parents.
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Registered trials
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.