title: Analysis of factors predicting success of metformin and clomiphene treatment for women with infertility owing to PCOS-related ovulation dysfunction in a randomised controlled trial.
abstract: BACKGROUND
  Metformin has failed to gain wide acceptance as a first-line treatment option for women with anovulatory infertility related to polycystic ovary syndrome. This study aimed to ascertain factors that predict fertility success with treatment that included metformin compared to standard (non-metformin) treatment.
  
  
  METHODS
  Randomised trial data analysis by logistic regression of factors likely to have a differential influence on the likelihood of success of metformin versus non-metformin treatment amongst women with ovulation dysfunction related to polycystic ovary syndrome.
  
  
  RESULTS
  metformin versus those receiving placebo and those with lower BMI who received metformin were more likely to become pregnant than their lower BMI counterparts who received placebo (P=0.039). The subpopulation of women with BMI≤32 kg/m(2) had no factors showing a significantly different impact on the chance of pregnancy for women treated with metformin versus those receiving clomiphene treatment or combination metformin/clomiphene treatment versus clomiphene treatment. There were no significantly different effects of free testosterone, fasting insulin, duration of infertility or ultrasound appearance of polycystic ovaries in any treatment groups.
  
  
  CONCLUSIONS
  This study provides preliminary evidence that BMI may be an important prognostic factor in response to metformin for women with ovulation dysfunction related to polycystic ovary syndrome, suggesting that women with a lower BMI may respond better to metformin treatment versus placebo amongst women with BMI>32 kg/m(2) . Individual patient data meta-analysis of existing randomised trials would clarify this further and would assess whether other factors might predict better response to metformin versus standard treatments.
authors.affiliation: Fertility Plus, Auckland District Health Board, and Department ofObstetrics & Gynaecology, University of Auckland, Auckland Hospital, Grafton, Auckland, New Zealand. n.johnson@auckland.ac.nz
authors.forename: Neil P
authors.initials: NP
authors.lastname: Johnson
authors.forename: Stephan
authors.initials: S
authors.lastname: Bontekoe
authors.forename: Alistair W
authors.initials: AW
authors.lastname: Stewart
mesh_terms: D000858:Anovulation / Q000188:drug therapy; D015992:Body Mass Index; D002996:Clomiphene / Q000627:therapeutic use*; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use*; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D008687:Metformin / Q000627:therapeutic use*; D011085:Polycystic Ovary Syndrome / Q000000981:diagnostic imaging / Q000188:drug therapy*; D011247:Pregnancy; D018873:Pregnancy Rate; D016032:Randomized Controlled Trials as Topic; D013739:Testosterone / Q000097:blood; D014463:Ultrasonography
chemical_list: D005300:Fertility Agents, Female; D007328:Insulin; D002996:Clomiphene; D013739:Testosterone; D008687:Metformin