Chinese herbal medicine and clomiphene citrate for anovulation: a meta-analysis of randomized controlled trials

The study objective was to investigate the efficacy of Chinese herbal medicine for improving standard infertility treatments.

A search of the literature between 2000 and 2006 was done in English and Chinese using the search terms anovulation, infertility, clomiphene citrate, Chinese herbal medicine, and randomized controlled trials. A review was done of 1009 studies with selection criteria including randomized controlled trials (RCTs) of Chinese herbal medicine combined with clomiphene citrate (CC) versus a control arm using CC alone with primary endpoints of changes in basal body temperatures, ovulation rates, endometrial lining, and pregnancy outcomes.

Fourteen (14) randomized studies representing 1316 patients met inclusion criteria. Four (4) studies (n = 315) reported 14% higher likelihood of biphasic basal body temperatures (risk ratios [RR] = 1.14; 95% confidence interval [CI], 1.00, 1.29). Six (6) studies (n = 604) reported a nonsignificant 18% increase in ovulation rates (RR = 1.18; 95% CI, 0.91, 1.52). Two studies (n = 138) reported subjects 78% more likely to have endometrial lining greater than 6 mm (RR = 1.78; 95% CI, 1.22, 2.60). Thirteen (13) studies (n = 1202) reported a 50% increase in pregnancy rates (RR = 1.50; 95% CI, 1.23, 1.84).

Chinese herbal medicine may increase the effectiveness of CC therapy. However, the RCTs are of poor methodological quality and small sample size, and the results require confirmation with rigorously controlled studies.