Trial reportReproductive biology and endocrinology : RB&E2020
The effect of letrozole versus artificial hormonal endometrial preparation on pregnancy outcome after frozen-thawed embryos transfer cycles: a randomized clinical trial.
Trial report in Reproductive biology and endocrinology : RB&E, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06372119 (Letrozole-stimulated Cycle Strategy Versus Artificial Cycle Strategy for Endometrial Preparation in Women With Irregular Menstrual Cycles), which is not on this map. Cited by 15 papers, 4 of them syntheses 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.
Letrozole-stimulated Cycle Strategy Versus Artificial Cycle Strategy for Endometrial Preparation in Women With Irregular Menstrual Cycles: A Randomized Controlled Trial
Who cites it
15 citing papers in PubMed, 4 syntheses or guidelines pooled it, 35 citations in OpenAlex.
- Investigation of trends, hot spots and effective therapies for pregnancy outcomes in polycystic ovary syndrome: a bibliometric analysis.Frontiers in medicine · 2026Pooled it
- Cycle regimens for endometrial preparation prior to frozen embryo transfer.The Cochrane database of systematic reviews · 2025Pooled it
- Ovulation-induced frozen embryo transfer regimens in women with polycystic ovary syndrome: a systematic review and meta-analysis.Journal of assisted reproduction and genetics · 2024Pooled it
- Systematic review update and meta-analysis of randomized and non-randomized controlled trials of ovarian stimulation versus artificial cycle for endometrial preparation prior to frozen embryo transfer in women with polycystic ovary syndrome.Reproductive biology and endocrinology : RB&E · 2022Pooled it
- Letrozole ovulation regimen for frozen-thawed embryo transfer in women with polycystic ovary syndrome: a muti-centre randomised controlled trial.Reproductive biology and endocrinology : RB&E · 2025Trial
- Letrozole-stimulated cycles versus hormone replacement treatment cycles for frozen embryo transfer in women with polycystic ovary syndrome: a prospective randomized controlled trial.Journal of assisted reproduction and genetics · 2025Trial
- Reproductive and obstetric outcomes following frozen embryo transfer: letrozole combined with human menopausal gonadotropin versus hormone replacement cycle.Frontiers in endocrinology · 2026Article
- Article
- Effect of different endometrial preparation methods on pregnancy outcome of FET in women with a normal menstrual cycle.Journal of family medicine and primary care · 2024Article
- Letrozole-stimulated endometrial preparation protocol is a superior alternative to hormone replacement treatment for frozen embryo transfer in women with polycystic ovary syndrome, a cohort study.Reproductive biology and endocrinology : RB&E · 2023Article
- The effect of mildly stimulated cycle versus artificial cycle on pregnancy outcomes in overweight/obese women with PCOS prior to frozen embryo transfer: a retrospective cohort study.BMC pregnancy and childbirth · 2022Article
- Ovulation induction regimens are associated with a higher rate of livebirth after frozen single-blastocyst transfer among women with polycystic ovary syndrome.Frontiers in endocrinology · 2022Article
- Comparison of Perinatal Outcomes of Letrozole-Induced Ovulation and Hormone Replacement Therapy Protocols in Patients With Abnormal Ovulation Undergoing Frozen-Thawed Embryo Transfer: A Propensity Score Matching Analysis.Frontiers in endocrinology · 2022Article
- Retrospective cohort study on preparation regimens for frozen embryo transfer.Reproduction & fertility · 2021Article
- Comparison of Pregnancy and Neonatal Outcomes of Single Frozen Blastocyst Transfer Between Letrozole-Induction and HRT Cycles in Patients With Abnormal Ovulation.Frontiers in endocrinology · 2021Article
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 4 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundConsidering that clinical trial studies are limited in polycystic ovary syndrome (PCOS) patients, and there is no consensus on an optimum endometrial preparation protocol for frozen embryo transfer (FET), the present study was designed as a randomized clinical trial to compare the reproductive outcomes following stimulated cycles with letrozole plus human menopausal gonadotropin (HMG) for endometrial preparation compared with routine AC-FET.
methodsThis randomized controlled trial was carried out on infertile PCOS patients who underwent IVF/ICSI and FET cycles in Arash Women's Hospital affiliated to Tehran University of Medical Sciences between September 2018 and January 2020. PCOS diagnosis was based on the Rotterdam criteria. Eligible patients were randomly allocated into two groups: stimulated cycle with letrozole plus (HMG) (intervention group) and routine artificial hormonal endometrial preparation (control group).
resultsOne hundred seventy-seven infertile patients were recruited for participation in the study. Of these, 57 women were excluded due to non-eligibility for entering the study, and a total of 120 patients were randomly assigned to two study groups. After follow up, the cycle outcomes of 57 patients in the intervention group and 59 patients in the control group were compared. The data analysis showed that the two groups did not have significant differences in fundamental and demographic characteristics. After the intervention, there were no significant differences in implantation rate, chemical, ectopic, and clinical pregnancy rates between groups. Moreover, the rates of miscarriage and ongoing pregnancy were similar between groups (P > 0.05).
conclusionsWe found similar pregnancy outcomes with two endometrial preparation methods. Noting that each treatment centre should select the most beneficial and cost-effective method with the least adverse effects for patients, letrozole preparations for FET could be incorporated into possible options; however, establishing this approach as first-line treatment is premature in light of current evidence, and future randomized clinical trials with larger sample sizes are required for widespread application.
trial registrationThe study was also registered in the Iranian Registry of Clinical Trials on March 20th, 2020. ( IRCT20090526001952N12 at www.irct.ir , registered retrospectively).
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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.