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

Objective: The aim of this literature search is to establish if metformin is efficacious when given to clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS) patients. Design: Medline 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 propspective 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 was P <.0001 with a 95% CI of 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.