ArticleReproductive biology and endocrinology : RB&E2023
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.
Article in Reproductive biology and endocrinology : RB&E, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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13 citing papers in PubMed, 25 citations in OpenAlex.
- 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
- Comparison of pregnancy outcomes and vaginal microbiota in women with endometriosis undergoing frozen embryo transfer using letrozole combined with HMG versus hormone replacement therapy with GnRH-a pretreatment.Journal of biomedical research · 2026Article
- Risk factors and treatment strategies for live birth in women with high BMI undergoing ART.BMC medicine · 2026Article
- The letrozole use in reproductive medicine: Beyond aromatase inhibition - a comprehensive review.Turkish journal of obstetrics and gynecology · 2026Article
- Reproductive and obstetric outcomes following frozen embryo transfer: letrozole combined with human menopausal gonadotropin versus hormone replacement cycle.Frontiers in endocrinology · 2026Article
- Ovulation induction or artificial programmed protocol: which endometrial preparation approach is more favorable in reducing obstetrical and neonatal complications for ovulation disorder patients undergoing frozen-thawed embryo transfer?Frontiers in endocrinology · 2026Article
- 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
- Impact of CYP2A6 genetic polymorphism on letrozole efficacy in Iraqi women with polycystic ovary syndrome.Journal of Taibah University Medical Sciences · 2025Article
- Comparing programmed, modified natural and natural cycle frozen embryo transfer on obstetric outcomes in polycystic ovary syndrome: a national cohort study.Journal of assisted reproduction and genetics · 2025Article
- Scoping Review of Letrozole in Assisted Reproductive Cycles: Efficacy and Outcomes Across Infertility Causes.Healthcare (Basel, Switzerland) · 2025Review
- Impact of different endometrial preparation protocols on pregnancy outcomes in patients at high risk for ovarian hyperstimulation syndrome: a propensity score matched retrospective cohort study.BMC pregnancy and childbirth · 2025Article
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12 authors at 3 institutions in 1 country.
Funding
Abstract
backgroundThe current routine endometrial preparation protocol for women with polycystic ovary syndrome (PCOS) is hormone replacement treatment (HRT). Letrozole is rarely used in frozen embryo cycles. Evidence confirming whether letrozole-stimulated (LS) protocol is suitable for frozen embryo transfer in patients with PCOS and for whom is suitable remains lacking.
methodsThis was a retrospective cohort study involving all frozen embryo transfer cycles with LS and HRT for PCOS during the period from Jan 2019 to December 2020 at a tertiary care center. Multivariate Logistic regression was used to analyze the differences in clinical pregnancy rate, live birth rate, miscarriage rate, the incidence of other pregnancy and obstetric outcomes between LS and HRT protocols after adjusting for possible confounding factors. Subgroup analysis was used to explore the population for which LS protocol was suitable.
resultsThe results of multivariate logistic regression showed that LS was significantly associated with a higher clinical pregnancy rate (70.9% vs. 64.4%;aOR:1.41, 95%CI: 1.18,1.68), live birth rate (60.5% vs. 51.4% aOR:1.49, 95%CI: 1.27,1.76), and a lower risk of miscarriage (14.7% vs. 20.1% aOR: 0.68, 95%CI: 0.53,0.89), hypertensive disorders of pregnancy (6.7% vs. 8.9% aOR: 0.63, 95%CI: 0.42,0.95), and gestational diabetes mellitus (16.7% vs. 20.7% aOR:0.71, 95%CI: 0.53,0.93) than HRT. There were no significant differences in other outcomes such as preterm birth, cesarean delivery, small for gestational age, or large for gestational age between the two endometrial preparation protocols. Subgroup analysis showed that LS had higher live birth rates than HRT in most of the subgroups; in the three subgroups of maternal age ≥ 35 years, menstrual cycle < 35 days, and no insulin resistance, the live birth rates of the two endometrial preparation protocols were comparable.
conclusionsLS protocol could improve the live birth rate and reduce the incidence of miscarriage, hypertensive disorders of pregnancy and gestational diabetes mellitus in patients with PCOS. LS protocol is suitable for all types of patients with PCOS. LS should be considered the preferred endometrial preparation protocol for women with PCOS.
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