Hello, Thanks for the query. I can understand your concerns. Thyronorm is the brand name levothyroxine. It is similar to your natural thyroid hormone. Thyronorm is safe and and it is unsafe not to take thyroid medication during pregnancy if you need it. Thyroid hormones are essential for physical and mental growth of your unborn baby and it does not cause any harm to the baby. Hypothyroidism during pregnancy can cause serious effects like growth retardation and impaired cognitive development in children. During pregnancy more thyroid hormone is needed both for you and your baby thats why the doctor wants to slightly increase the dose. The exact dose of medication needed will be based on your TSH and never skip this medicine especially when you are pregnancy. Hope I have answered your query. Regards. Dr.Shinas Hussain