The letrozole use in reproductive medicine: Beyond aromatase inhibition - a comprehensive review.
| Title: | The letrozole use in reproductive medicine: Beyond aromatase inhibition - a comprehensive review. |
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| Authors: | Aydın G; İstanbul Health and Technology University Faculty of Medicine, Department of Obstetrics and Gynecology, İstanbul, Türkiye.; Eurofertil IVF Center, Bursa, Türkiye.; Hatırnaz Ş; Kent University School of Health Sciences, İstanbul, Türkiye.; Saynur Hatırnaz E; Maltepe University Faculty of Medicine, Department of Histology and Embryology, İstanbul, Türkiye.; Çetinkaya MB; Medical Park Samsun Hospital, IVF Center, Samsun, Türkiye.; Akdeniz M; Medical Park Samsun Hospital, IVF Center, Samsun, Türkiye.; Dokuzeylül Güngör N; Bahçeşehir University Faculty of Medicine, Department of Obstetrics and Gynecology, İstanbul, Türkiye.; Güler O; Private Gazi Hospital, Clinic of Obstetrics and Gynecology, İstanbul, Türkiye.; Merdanoğlu MA; Yunus Emre State Hospital, IVF Center, Eskişehir, Türkiye.; Uzun A; Medipol University Faculty of Medicine, Department of Obstetrics and Gynecology, İstanbul, Türkiye.; Eroğlu S; Samsun University Faculty of Medicine, Department of Obstetrics and Gynecology, Samsun, Türkiye.; Tosun Ö; University of Health Sciences Türkiye, Zeynep Kamil Maternity and Children Training and Research Hospital, İstanbul, Türkiye.; Bahadırlı A; Bursa City Hospital, Bursa, Türkiye.; Yurtçu E; Düzce University Faculty of Medicine, Department of Obstetrics and Gynecology, Düzce, Türkiye.; Keyif B; Düzce University Faculty of Medicine, Department of Obstetrics and Gynecology, Düzce, Türkiye.; Güvey H; Kütahya Health Sciences University Faculty of Medicine, Department of Medical Education and Informatics, Kütahya, Türkiye.; Gürkan N; Medical Park Samsun Hospital, IVF Center, Samsun, Türkiye.; Karlı P; Private Office, Samsun, Türkiye.; Yılmaz Z; Private Clinic, Samsun, Türkiye.; Baldini GM; MOMO' FertiLIFE, IVF Clinic, Bisceglie, Italy.; Tavuz Aİ; Momart IVF Center, İstanbul, Türkiye.; Sparic R; Faculty of Medicine, University of Belgrade, Belgrade, Serbia.; Clinic for Gynecology and Obstetrics, University Clinical Centre of Serbia, Belgrade, Serbia.; Tabakova N; Medical University of Varna, Varna, Bulgaria.; Tinelli A; Department of Obstetrics and Gynecology, 'Veris delli Ponti' Hospital, CEntro di RIcerca Clinico SALentino (CERICSAL), 'Veris delli Ponti' Hospital, Scorrano, Italy.; Cao M; Department of Obstetrics and Gynecology, 'Veris delli Ponti' Hospital, CEntro di RIcerca Clinico SALentino (CERICSAL), 'Veris delli Ponti' Hospital, Scorrano, Italy.; Ta SL; Originelle Women's Health and Fertility Center, Quebec, Canada.; Hatırnaz O; Ondokuz Mayıs University Faculty of Medicine, Samsun, Türkiye.; Dahan M; Reproductive Medicine Center, McGill University Faculty of Medicine, Quebec, Canada. |
| Source: | Turkish journal of obstetrics and gynecology [Turk J Obstet Gynecol] 2026 Mar 05; Vol. 23 (1), pp. 101-114. Date of Electronic Publication: 2026 Feb 17. |
| Publication Type: | Journal Article |
| Language: | English |
| Journal Info: | Publisher: Galenos Yayınevi Country of Publication: Turkey NLM ID: 101656661 Publication Model: Print-Electronic Cited Medium: Print ISSN: 2149-9322 (Print) Linking ISSN: 21499330 NLM ISO Abbreviation: Turk J Obstet Gynecol Subsets: PubMed not MEDLINE |
| Imprint Name(s): | Original Publication: Fındıkzade-İstanbul, Turkey : Galenos Yayınevi |
| Abstract: | Letrozole and other aromatase inhibitors are increasingly recognized as first-line ovulation induction (OI) medications, offering an efficient and physiologic approach to ovarian stimulation that enhances outcomes in reproductive medicine. By selectively inhibiting aromatase and maintaining lower peripheral estrogen levels, letrozole supports mono- or bi-follicular development while reducing the risk of supraphysiologic estradiol exposure seen with traditional gonadotropin regimens. These pharmacological characteristics have contributed to its expanding use not only in OI but also in various assisted reproductive technologies. To evaluate the clinical benefits, effectiveness, and safety of using letrozole in in vitro fertilization (IVF), in vitro maturation (IVM), and OI, with particular attention to reproductive outcomes, ovarian response, endometrial effects, cycle characteristics, and treatment-related adverse events. A comprehensive systematic search covering the period from December 2000 to November 2025 was conducted across major electronic databases including PubMed, Embase, the Cochrane Library, and Google Scholar. The search strategy incorporated predefined keywords related to letrozole, aromatase inhibition, OI, IVF, and IVM. Studies involving randomized controlled trials, observational cohorts, and meta-analyses were included, while non-clinical and non-reproductive data were excluded. Relevant outcomes were extracted and synthesized qualitatively. Letrozole demonstrates broad clinical utility in reproductive medicine, spanning assisted reproductive techniques, ovarian stimulation strategies, and the management of ovarian hyperstimulation syndrome risk, ectopic pregnancy, and endometriosis-related infertility. Its targeted estrogen suppression, cost-effectiveness, and favorable safety profile make it a valuable component of individualized treatment protocols. Nonetheless, further high-quality research is required to refine optimal dosing strategies, identify ideal patient populations, and clarify long-term reproductive and obstetric safety.; (Copyright© 2026 The Author(s). Published by Galenos Publishing House on behalf of Turkish Society of Obstetrics and Gynecology.) |
| Competing Interests: | No conflict of interest was declared by the authors. |
| Contributed Indexing: | Keywords: Letrozole; assisted reproductive medicine; in vitro fertilization; in vitro maturation; infertility; Local Abstract: [Publisher, Turkish] Letrozol ve diğer aromataz inhibitörleri, giderek artan biçimde birinci basamak ovülasyon indüksiyonu (Oİ) ajanları olarak kabul edilmekte olup, üreme tıbbında sonuçları iyileştiren etkili ve fizyolojik bir over stimülasyon yaklaşımı sunmaktadır. Aromatazı selektif olarak inhibe ederek periferal östrojen düzeylerini düşürmesi, geleneksel gonadotropin protokollerinde görülen suprafizyolojik östradiol maruziyetini azaltırken, mono- veya bifolliküler gelişimi desteklemektedir. Bu farmakolojik özellikler, letrozolün yalnızca Oİ’de değil, çeşitli yardımcı üreme tekniklerinde de kullanım alanının genişlemesine katkı sağlamıştır. Letrozolün in vitro fertilizasyon (IVF), in vitro maturasyon (IVM) ve Oİ’deki klinik faydalarını, etkinliğini ve güvenlilik profilini değerlendirmek; özellikle üreme sonuçları, over yanıtı, endometriyal etkiler, siklus karakteristikleri ve tedaviye bağlı advers olaylara odaklanmak. Aralık 2000 ile Kasım 2025 dönemini kapsayan kapsamlı bir sistematik tarama, PubMed, Embase, Cochrane Library ve Google Scholar gibi temel elektronik veri tabanlarında gerçekleştirilmiştir. Arama stratejisinde letrozol, aromataz inhibisyonu, Oİ, IVF ve IVM ile ilgili önceden belirlenmiş anahtar kelimeler kullanılmıştır. Randomize kontrollü çalışmalar, gözlemsel kohortlar ve meta-analizler dahil edilmiş; klinik dışı ve üreme tıbbıyla ilişkili olmayan veriler dışlanmıştır. İlgili sonuçlar çıkarılmış ve niteliksel olarak sentezlenmiştir. Letrozol, yardımcı üreme tedavileri, over stimülasyon stratejileri ve yumurtalık hiperstimülasyon sendromu risk yönetiminden ektopik gebelik ve endometriozis ilişkili infertiliteye kadar geniş bir klinik kullanım yelpazesi göstermektedir. Hedefe yönelik östrojen baskılanması, maliyet etkinliği ve olumlu güvenlilik profili ile bireyselleştirilmiş tedavi protokollerinin değerli bir bileşenidir. Bununla birlikte, optimal dozlama stratejilerinin netleştirilmesi, ideal hasta gruplarının belirlenmesi ve uzun dönem üreme ile obstetrik güvenliğin aydınlatılması için daha yüksek kaliteli çalışmalara ihtiyaç vardır. |
| Entry Date(s): | Date Created: 20260217 Date Completed: 20260305 Latest Revision: 20260308 |
| Update Code: | 20260308 |
| PubMed Central ID: | PMC12963804 |
| DOI: | 10.4274/tjod.galenos.2026.02391 |
| PMID: | 41700008 |
| Database: | MEDLINE |
Journal Article