Hi and welcome to HCM. progesterone (such as Susten) is not approved for use during pregnancy in any advanced country such as US, UK etc. Some authorities in the past used to recommend its use in recurrent miscarriage or threatened abortion but now there is now no evidence of any benefit from such practice and recommend against the use in early pregnancy unless there is proven deficiency. Susten is given only in women likely to have / proven progesterone (luteal phase) deficiency. One problem with this medicine is that female baby may suffer from hirsutism (unwanted hair on face, chest etc). Therefore if at all progsterones have to be given when there is documented deficiency, it is preferable to give dydrogesterone (sold as Duphaston) or medroxyprogesterone (sold as Meprate). I suggest you to consult your doctor regarding this and ask him politely about this, if his answer is convincing you can continue using this drug. All the best Regards Dr Santosh