title: RETRACTED: Letrozole versus combined metformin and clomiphene citrate for ovulation induction in clomiphene-resistant women with polycystic ovary syndrome: a randomized controlled trial.
abstract: This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
  
  This article has been retracted at the request of the ASRM Publications Committee.
  
  Several reports of randomized clinical trials were recently the subject of an investigation conducted by the publications committee of the ASRM. The committee reviewed concerns related to the validity of data reported in those reports. The committee noted significant duplication of data reported in this manuscript with data reported in another report (PMID 17686479; https://doi.org/10.1016/j.fertnstert.2007.05.010) pertaining to a different study group that could not be explained. As we cannot vouch for the validity of the data, we have issued a retraction of this paper.
authors.affiliation: Departments of Obstetrics & Gynecology, Mansoura University, Mansoura, Egypt. Electronic address: hatem_ah@hotmail.com.
authors.forename: Hatem
authors.initials: H
authors.lastname: Abu Hashim
authors.affiliation: Departments of Obstetrics & Gynecology, Mansoura University, Mansoura, Egypt.
authors.forename: Tarek
authors.initials: T
authors.lastname: Shokeir
authors.affiliation: Departments of Obstetrics & Gynecology, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Badawy
mesh_terms: D000328:Adult; D000465:Algorithms; D002996:Clomiphene / Q000008:administration & dosage*; D004338:Drug Combinations; D004351:Drug Resistance / Q000187:drug effects; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007247:Infertility, Female / Q000188:drug therapy* / Q000209:etiology; D000077289:Letrozole; D008687:Metformin / Q000008:administration & dosage*; D009570:Nitriles / Q000627:therapeutic use*; D010062:Ovulation Induction / Q000379:methods*; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy*; D011247:Pregnancy; D016896:Treatment Outcome; D014230:Triazoles / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D004338:Drug Combinations; D005300:Fertility Agents, Female; D007004:Hypoglycemic Agents; D009570:Nitriles; D014230:Triazoles; D002996:Clomiphene; D000077289:Letrozole; D008687:Metformin