Luteal phase deficiency: effect of treatment on pregnancy rates.

Luteal phase deficiency is thought to be a cause of female infertility. Nevertheless, little agreement exists concerning either its diagnosis or its treatment. To address the latter question, we reviewed the English literature and examined the effect of treatment on pregnancy rates. One randomized controlled trial found a statistically insignificant benefit of treatment with progesterone suppositories or oral dehydroprogesterone versus no treatment (relative risk 1.9; 95% confidence interval 0.4 to 8.1). Three other comparative studies also showed no statistically significant benefit. Case-series reports (before-after studies) claiming benefit failed to account for the effect of regression to the mean. The benefit of treatment for luteal phase deficiency has not been established. Uniform case definitions and randomized controlled trials of adequate power are needed to resolve this problem.