You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Screening of neonatal thyroid disease is done by and explain in detail?
Since the neonates are asymptomatic at bih all newborns are screened for neonatal hypothyroidism. TSH is estimated either in cord blood at the time of bih (preferred) or blood obtained from heel prick after 2 days of bih.(Refer: Nelson's Textbook of Pediatrics, SAE, 1st edition, pg no. 2669 - 2773)