ArticleBMC pregnancy and childbirth2022
Letrozole-induced endometrial preparation improved the pregnancy outcomes after frozen blastocyst transfer compared to the natural cycle: a retrospective cohort study.
Article in BMC pregnancy and childbirth, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06181305 (Hormonal Replacement Therapy Plus Letrozole Incorporation Versus Letrozole Mild Ovarian Stimulation in Endometrial Preparation for Frozen Embryo Transfer), which is not on this map. Cited by 8 papers.
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The trial behind it
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Hormonal Replacement Therapy Plus Letrozole Incorporation Versus Letrozole Mild Ovarian Stimulation in Endometrial Preparation for Frozen Embryo Transfer: A Randomised Controlled Trial
Who cites it
8 citing papers in PubMed.
- Comparison of frozen embryo transfer outcomes in hormonal vs. mild stimulation protocols in polycystic ovary syndrome women: A randomized controlled trial.International journal of reproductive biomedicine · 2025Article
- Scoping Review of Letrozole in Assisted Reproductive Cycles: Efficacy and Outcomes Across Infertility Causes.Healthcare (Basel, Switzerland) · 2025Review
- Diverse developmental velocities of blastocyst development emerge as early as a few hours after insemination: morphokinetic analysis of fertilisation in days 4-7 blastocysts.Journal of assisted reproduction and genetics · 2025Article
- Does hCG-trigger in the mild stimulation protocol for endometrial preparation have any effect on pregnancy outcome in frozen-thawed embryo transfer?Reproductive biology and endocrinology : RB&E · 2024Article
- Maternal and obstetric outcomes following the transfer of embryos warmed with fatty acid-supplemented solutions.BMC pregnancy and childbirth · 2024Article
- Fatty acid supplementation during warming improves pregnancy outcomes after frozen blastocyst transfers: a propensity score-matched study.Scientific reports · 2024Article
- Comparison of 1-year cumulative live birth and perinatal outcomes following single blastocyst transfer with or without preimplantation genetic testing for aneuploidy: a propensity score-matched study.Journal of assisted reproduction and genetics · 2023Article
- Fatty acid supplementation into warming solutions improves pregnancy outcomes after single vitrified-warmed cleavage stage embryo transfers.Reproductive medicine and biologyArticle
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5 authors.
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Abstract
backgroundLetrozole treatment is considered an effective option in endometrial preparation for frozen embryo transfers in patients with ovulation disorders or irregular menstruation; however, the effectiveness of letrozole-induced endometrial preparation remains unclear in ovulatory patients. Furthermore, there is no comparative study reporting on pregnancy complications and congenital anomalies after frozen embryo transfers comparing natural and letrozole-assisted cycles. This study examined whether letrozole-induced endometrial preparation affected pregnancy outcomes, perinatal outcomes, and congenital anomalies after single vitrified-warmed blastocyst transfers (SVBTs) in ovulatory patients, as compared with the natural cycle.
methodsThis historic cohort study included only patients with unexplained infertility. Overall, 14,611 patients who underwent SVBTs between July 2015 and June 2020, comprising both natural and letrozole-assisted cycles, were included. Multiple covariates that impact outcomes were used for propensity score matching; 1,911 patients in the letrozole group were matched to 12,700 patients in the natural group, and the clinical records of 1,910 patients in each group were retrospectively analysed. Cycle characteristics, pregnancy outcomes (clinical pregnancy, ongoing pregnancy, and live birth), and incidence of pregnancy complications and congenital anomalies were statistically compared between the two groups.
resultsMultivariate logistic regression analysis showed that letrozole administration during SVBT cycles significantly improved the live birth rate (P = 0.0355). Gestational age, birth length, birth weight, and infant sex, as well as the incidence of pregnancy complications and birth defects, were statistically comparable between the two groups. Furthermore, multivariate logistic regression analysis revealed that the perinatal outcomes were not affected by letrozole-induced endometrial preparation.
conclusionsLetrozole-induced endometrial preparation improved the live birth rate compared with the natural cycle, without adverse effects on perinatal outcomes and congenital anomalies after SVBTs. Therefore, letrozole-induced endometrial preparation might be a safe and more effective strategy, especially for patients with insufficient luteal function.
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