Is the addition of metformin efficacious in the treatment of clomiphene citrate-resistant patients with polycystic ovary syndrome? A structured literature review

ObjectiveThe aim of this literature search is to establish if metformin is efficacious when given to clomiphene citrate (CC)–resistant polycystic ovary syndrome (PCOS) patients.DesignMedline database was searched from 1 January 1980 to 1 January 2005. Inclusion criteria were prospective randomized control trials where metformin was randomized either with placebo or CC to induce ovulation in the CC-resistant patient.Result(s)Group 1: Four trials were prospective double-blind placebo controlled. When the data of the four trials were pooled, the overall effect of the addition of metformin in the CC patient was P=.0006 with a 95% confidence interval (CI) of odds ratio (OR) 1.81–8.84. Group 2: In two trials the randomization was only prospective. When the data of these two trials were pooled, the overall effect of the addition of metformin in the CC-resistant patient was P<.0001 with a 95% CI of OR 6.24–70.27. Groups 1 and 2: The combined data show an overall effect of P<.0001 with a 95% CI of OR 3.59–12.96.Conclusion(s)The addition of metformin in the CC-resistant patient is highly effective in achieving ovulation induction.