Progesterone from an unexpected source may affect miscarriage risk

About twenty percent of confirmed pregnancies end in miscarriage, most often in the first trimester, for reasons ranging from infection to chromosomal abnormality. But some women have recurrent miscarriages, a painful process that points to underlying issues. Clinical studies have been uneven, but some evidence shows that for women with a history of recurrent miscarriage, taking progesterone early in a pregnancy might moderately improve these women's chances of carrying a pregnancy to term.

source https://www.lifetechnology.com/blogs/life-technology-medical-news/progesterone-from-an-unexpected-source-may-affect-miscarriage-risk