Hypothyroidism in early pregnancy may also cause low progesterone, as both are part of the endocrine system and affect each other. Whether it is hypothyroidism or low progesterone, it is recommended to actively treat it accordingly, otherwise it may lead to miscarriage. In addition, before planning to get pregnant, you need to do the thyroid function test, do the sex hormone six tests, if you find that there is hypothyroidism or low progesterone, you need to give the appropriate treatment, after correcting the need for medication to control before getting pregnant, the whole safety of the pregnancy will be improved, the pregnancy should be done on a regular basis to the appropriate examination.