title: In vitro fertilization pregnancy rates in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction disorders.
abstract: BACKGROUND
  Untreated hypothyroidism can lead to ovulatory dysfunction resulting in oligo-amenorrhea. Treatment with levothyroxine can reverse such dysfunction and thus should improve fertility. The purpose of this retrospective study was to assess whether in vitro fertilization (IVF) pregnancy rates differ in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction/disorders.
  
  
  METHODS
  Treated hypothyroid and euthyroid women undergoing IVF at an academic IVF center were studied after Institutional Review Board approval. Women with hypothyroidism were treated with levothyroxine 0.025-0.15 mg/day for at least 3 months to maintain baseline thyrotropin (TSH) levels of 0.35-4.0 μU/mL prior to commencing IVF treatment (HYPO-Rx group). Causes of infertility were similar in both groups with the exception of male factor, which was more common in the HYPO-Rx group. The main outcomes studied were implantation rate, clinical pregnancy rate, clinical miscarriage rate, and live birth rate.
  
  
  RESULTS
  We reviewed the first IVF retrieval cycle performed on 240 women aged 37 years or less during the period January 2003 to December 2007. Women with treated hypothyroidism (n=21) had significantly less implantation, clinical pregnancy, and live birth rates than euthyroid women (n=219).
  
  
  CONCLUSIONS
  We conclude that, despite levothyroxine treatment, women with hypothyroidism have a significantly decreased chance of achieving a pregnancy following IVF compared to euthyroid patients. A larger prospective study is necessary to assess confounding variables, confirm these findings, and determine the optimal level of TSH prior to and during controlled ovarian hyperstimulation for IVF.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Illinois College of Medicine, 820 South Wood St., Chicago, IL 60612-7313, USA. bscocc@uic.edu
authors.forename: Bert
authors.initials: B
authors.lastname: Scoccia
authors.forename: Habibe
authors.initials: H
authors.lastname: Demir
authors.forename: Yuna
authors.initials: Y
authors.lastname: Kang
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Fierro
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Winston
mesh_terms: D000328:Adult; D000568:Amenorrhea / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D007247:Infertility, Female / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000188:drug therapy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use*
chemical_list: D013972:Thyrotropin; D013974:Thyroxine