TSH (thyroid stimulating hormone) tests are routinely ordered for newborns as part of the screening program to diagnose the thyroid disorder and enable the treatment of infants with congenital (present at birth) hypothyroidism. THS test is a common blood test used to evaluate how well the thyroid gland is working. The thyroid gland is located at the lower front of the neck. TSH is produced by the pituitary, a pea-sized gland located at the base of the brain.