Hi, Thanks for posting in HCM. Duphaston is Dydrogesterone. It is an orally active progesterone hormone used to treat a wide variety of gynaecological conditions like menstrual disorders, infertility, threatened and habitual abortion, endometriosis, premenstrual syndrome and for hormone replacement therapy. Since it maintains the womb lining, it is useful in helping prevent miscarriage (spontaneous abortion) in women who have suffered repeated miscarriages or who may miscarry. The doctor might have advised you to take it just to be on safer side. Hope this information provided would be useful. All the best.