With the TSH increasing instead of decreasing, I'd definitly get the baby in for further blood work of the actual thyroid hormone levels with a pediatric endocrinologist.TSH(Thyroid Stimulating Hormone)is actually a signal from the pituitary gland released into the blood to stimulate the thyroid to produce more thyroid hormone for the brain and body. When this is elivated, it is a warning signal that the thyroid may not be producing enough on its own. Sometimes babies glands are a little sluggish, however, sometimes there is a real issue like with my daughter who was born without one. The real seriousness of it all and the reason why it's not advised to take any chances or wait too long, is that proper brain and body growth only happens when there is enough thyroid hormone available to the body. Babies brains and body growth are dependent upon this! You don't want to take any chances as 90% of brain growth happens within the first two years of life. If needed, thyroid hormone replacement should be started as soon as possible. My daughter started Synthroid at the age of 3 weeks and she has developed normally. Had we waited too long, this would not have been the case.