Hi Smita, I understand your concern. Thyroid hormone is important for fetal growth, & it should be in sufficient amount in mother s system during pregnancy. It s need increases in pregnancy due to fetal demands. It s good that you have already detected & treated thyroid problem, the thyroid hormone is well maintained before conception.You can very well plan pregnancy, * But please note, thyroid function tests need to be assessed while pregnancy & does of the thyroxin adjusted nicely, so as to provide it for fetal growth. SO - - please get pregnancy check up done regularly, - Consult endocrinologist as per your treating doctor s advise. Thanks