Which anti thyroid drug can be safely used in pregnancy

Ans. is 'a' i.e., Propylthiouracil This question has been repeated several times before, remember these important pointsAll antithyroid drugs can cross placenta so risk of fetal hypothyroidism and goitre is always thereBoth carbimazole and propylthiouracil can be used during pregnancy, but propylthiouracil is the drug of choice because its greater protein binding allows low doses of propylthiouracil to be transferred across the placenta and therefore less chance of hypothyroidism.The lowest effective dose of propyl thiouracil should be given and it is often possible to stop treatment in the last trimester since TSH Receptor antibodies tend to decline in pregnancy.Radioactive iodine is C/I during pregnancyIt can destroy the fetal thyroid tissue resulting in cretinismCarbimazole and methimazole have been associated with rare cases of foetal aplasia cutis.