Does using progesterone reduce the miscarriage rate in high risk pregnancies?

This study is testing whether taking progesterone (a natural female hormone) in early pregnancy can reduce the chance of miscarriage in women who have had difficulty getting or staying pregnant. Progesterone helps prepare and maintain the lining of the womb during pregnancy, and some researchers believe low levels may contribute to miscarriage. Women who take part will receive either progesterone or a placebo (dummy treatment) in early pregnancy. You may be eligible if: - You are a woman aged 18 or older - You have a confirmed pregnancy of less than 7 weeks - You have previously struggled to conceive (no pregnancy after 12 months of trying), OR have had 3 or more miscarriages You may NOT be eligible if: - You became pregnant through assisted reproductive technologies (IVF, IUI, etc.) Talk to your doctor about whether this trial might be right for you.