Is there evidence that progesterone may prevent some miscarriages?
Progestogens, including natural progesterone, may slightly decrease the chance of miscarriage in at-risk women. Progesterone thickens the uterine lining in preparation for pregnancy and helps nurture the fetus.
In a 2017 meta-analysis of 13 clinical trials involving 2,556 women who experienced recurring miscarriages, progestogen was found to lower the chance of miscarriage from 27.5% to 20.1%, though the findings were based on "evidence of only moderate quality." A 2013 review of previous studies found "no evidence to support the routine use of progestogens" for treating the threat of miscarriage. It acknowledges studies that found that it might be a successful therapy for women who miscarry frequently, but criticized those studies' methods.