title: Body mass index-associated differences in response to ovulation induction with letrozole.
abstract: OBJECTIVE
  To compare occurrence of pregnancy among obese (body mass index [BMI] ≥30) and nonobese (BMI <30), infertile women undergoing ovulation induction with the aromatase inhibitor letrozole followed by intrauterine insemination (IUI).
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Academic reproductive endocrinology and infertility clinic.
  
  
  METHODS
  Ninety women with a variety of infertility diagnoses.
  
  
  METHODS
  Letrozole (5 mg) on menstrual cycle days 3-7, followed by intrauterine insemination (IUI).
  
  
  METHODS
  Occurrence of pregnancy and pregnancy outcomes.
  
  
  RESULTS
  Ninety women underwent 180 letrozole-IUI cycles. Conception of pregnancy occurred in 10.4% and 18.2% of the BMI <30 and BMI ≥30 groups, respectively. Using BMI as a continuous variable showed a pregnancy odds ratio of 1.093 (confidence interval 1.008-1.184) for each unit increase in BMI. Incidence of miscarriage, multiple births, number of mature follicles, and presence of LH surge were similar between groups.
  
  
  CONCLUSIONS
  Our study of 90 women undergoing letrozole-IUI treatment showed greater likelihood of pregnancy in higher-BMI women, although the difference was not significant. Letrozole is an effective ovulation induction agent in higher-BMI women.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Alabama, Birmingham, Alabama, USA. kkmcknight@gmail.com
authors.forename: Katherine K
authors.initials: KK
authors.lastname: McKnight
authors.forename: James L
authors.initials: JL
authors.lastname: Nodler
authors.forename: John J
authors.initials: JJ
authors.lastname: Cooper
authors.forename: Victoria R
authors.initials: VR
authors.lastname: Chapman
authors.forename: Suzanne P
authors.initials: SP
authors.lastname: Cliver
authors.forename: Gordon Wright
authors.initials: GW
authors.lastname: Bates
mesh_terms: D000328:Adult; D000407:Alabama; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D015992:Body Mass Index; D016009:Chi-Square Distribution; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use*; D006801:Humans; D007247:Infertility, Female / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D007315:Insemination, Artificial; D000077289:Letrozole; D016015:Logistic Models; D009570:Nitriles / Q000627:therapeutic use*; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D016017:Odds Ratio; D010053:Ovary / Q000187:drug effects* / Q000503:physiopathology; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D016896:Treatment Outcome; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D047072:Aromatase Inhibitors; D005300:Fertility Agents, Female; D009570:Nitriles; D014230:Triazoles; D000077289:Letrozole