Hello. welcome to HCM. yes, a hypothyroid state if left untreated effects the baby. It is best to be euthyroid before getting pregnant and by maintaining it throughout pregnancy. In addition it is important to check the baby for thyroid as soon as possible after birth, which is a standard practice in most hospitals these days. Effective weight reduction will follow the same norms as for a non-hypothyroid person. eat healthy and exercise regularly. You have to take advice of your endocrinologist and homeopath doctor both, if you want to continue both medicines in parallel. Take care.