Progesterone is essential for the maintenance of pregnancy. Several small trials have
suggested that progesterone supplementation may reduce the risk of miscarriage in women
with recurrent or threatened miscarriage. Cochrane Reviews summarized the evidence and
found that the trials were small with substantial methodologic weaknesses. Since then, the
effects of first-trimester use of vaginal micronized progesterone have been evaluated in 2
large, high-quality, multicenter placebo-controlled trials, one targeting women with …