This commentary reflects on the effectiveness of progesterone in early pregnancy complications. Several studies have investigated the role of progesterone in women with bleeding in early pregnancy and in women with recurrent miscarriages. These publications suggests that first trimester use of progesterone is not effective to prevent miscarriages when there is blood loss in the first trimester, and that it is also not effective to prevent new miscarriages in women with recurrent miscarriages in their history. However, subgroup analysis tells us it might be effective to prevent new miscarriages in women with blood loss in the first trimester and three earlier miscarriages. Expert groups in the Netherlands are currently considering recommendations on the prescription of progesterone for women with early pregnancy complications.