Background: Both selective estrogen receptor modulators, tamoxifen and clomiphene have been used for ovulation induction for patients with anovulatory infertility. This meta-analysis sought to compare the effectiveness of tamoxifen to clomiphene for the induction of ovulation and achievement of pregnancy.
Methods: We searched MEDLINE, BIOSIS, PreMEDLINE, CINAHL, International Pharmaceutical Abstracts, DDSR, ACP Journal Club, DARE and CCTR, along with reference lists and national experts. Inclusion criteria were prospective clinical trials, which compared tamoxifen and clomiphene for ovulation induction in infertile couples with isolated anovulatory infertility. Main outcome measures were ovulation rate and clinical pregnancy rate. Pooled odds ratios were obtained using random effects meta-analysis.
Results: Four trials were included. After pooling all the trials, the use of tamoxifen or clomiphene citrate resulted in similar ovulation rates [odds ratio (OR) 0.755, 95% confidence interval (CI) 0.513-1.111]. There was no benefit of tamoxifen over clomiphene citrate in achievement of pregnancy per cycle (OR 1.056, 95% CI 0.583-1.912) or per ovulatory cycle (OR 1.162, 95% CI 0.632-2.134).
Conclusions: Clomiphene citrate and tamoxifen are equally effective in inducing ovulation. Although data regarding pregnancy rates and outcome are limited, there does not appear to be a significant benefit of one medication over the other.