Dear member, Thanks for writing to healthcare magic. thyroid hormone is naturally produced by the body and is required for all body functions especially pregnancy and fetal(baby) growth. women especially pregnant May sometimes have thyroid deficiencies as the mother s thyroid gland is not able to cope with the extra demand from baby. your doctor is right in prescribing you thyroid supplements. It is very important for your baby especially its brain and intelligence growth. I regularly screen my clinin pregnant patients for thyroid problem and prescribe thyronorm. There can be no side effects from thyroid supplements . Consult your doctor as the dose has to be increased or decreased depending on further blood tests. I would recommend repeat TSH,Free T3,FreeT4 after 6 weeks. kindly write back if any queries. Thanks. Dr Bhagyashree.