When parents find out that their child has been diagnosed with congenital hypothyroidism usually one of the first questions we ask is “Will my child have to be on this medicine for life?” The pediatric endocrinologist then launches into an explanation of transient congenital hypothyroidism. Transient congenital hypothyroidism is abnormal thyroid function, which later reverts to normal. There is some debate within the medical community as to whether infants who have abnormal thyroid function on newborn screens but have subsequent test results showing that the thyroid function has become normal should be considered to have had transient congenital hypothyroidism. For the most part, though, transient congenital hypothyroidism is defined as those patients who withdrew treatment after 3 years of age and assessment of thyroid function revealed normal thyroid function. For parents of children with congenital hypothyroidism, all we hear is that our child has the possibility of growing out of hypothyroidism. We cling to the hope that maybe one day our child (or children in my case) will be one of the lucky ones that will grow out of thyroid troubles.
The way this works is that when your congenital hypothyroid child is around age 3, they will have an ultrasound of their thyroid gland (if they haven’t already). This will let you and your pediatric endocrinologist know if there is any thyroid tissue. If there is no thyroid gland or a malformed thyroid gland, then your child’s doctor will probably tell you that you don’t need to bother with a trial off medication. If there is a normal looking thyroid gland, then your doctor will probably suggest that you do a trial off the medication (Synthroid, Levothyroxine, etc.) to see if your child has the transient type of hypothyroidism and has outgrown the need for the medication. Your doctor may recommend that your child go off the medication entirely or go to half of their current dose and taper the dose down. Now, I’m basing this off of my own experience and not every doctor does this exactly the same. Do not do this on your own. A trial off the medication should only be done at the direction of your child’s doctor and under their supervision.
When my son was 3 years old, he had an ultrasound of his thyroid gland. It was a very quick and easy procedure. We explained to him ahead of time that they were going to be taking pictures of his thyroid. Since he’d been to the doctor a lot, he was a bit nervous, but we reassured him that it would not hurt. The results of the ultrasound revealed that he had a perfectly normal looking thyroid gland. He had also been on the same dose of Synthroid for nearly a year. So, under our Doctor’s recommendation and supervision, we decided to move forward with the trial off Synthroid. We stopped giving him his daily medication and at the end of 4 weeks, he had a blood test done to check his thyroid levels. I still remember getting the call from his doctor telling us the results of the blood test. It stands out because she called at night, which only happens when something bad is going on. She said that he would have to be on Synthroid for the rest of his life and said we needed to start back on the Synthroid the very next day so that we could bring his thyroid levels back to normal. I will be honest and tell you that I cried. I was really hoping that he would outgrow it, but I also knew in my heart that the likelihood wasn’t that great that he would be one of the “lucky” ones because I had already noticed symptoms of hypothyroidism.
We have not done a trial off Levothyroxine with my youngest for two reasons. The first is that he has not been as stable on the medication and hasn’t needed to lower his dose in a while. The second reason is that we now know that my husband and I both have autoimmune thyroid disorders and both kids were born with thyroid disorders, so we feel that it would be very unlikely for our youngest to grow out of hypothyroidism. We are fairly certain that our children’s thyroid problems are genetic. If we do a trial off Synthroid with our youngest, we will request that it be a taper down instead of just coming off the medication entirely.
What does the PI say?
The Prescribing Information for Synthroid/Levothyroxine (“PI”) suggests a trial off Synthroid for children who have not been diagnosed with “permanent hypothyroidism”, in other words children who have thyroid glands that appear to be normal but aren’t functioning. The PI states that this should not be done until after age 3. Because it is so specific, I have included the text here so that you can read it yourself:
“In children in whom a diagnosis of permanent hypothyroidism has not been established, it is recommended that levothyroxine administration be discontinued for a 30-day trial period, but only after the child is at least 3 years of age. Serum T4 and TSH levels should then be obtained. If the T4 is low and the TSH high, the diagnosis of permanent hypothyroidism is established, and levothyroxine therapy should be reinstituted. If the T4 and TSH levels are normal, euthyroidism may be assumed and, therefore, the hypothyroidism can be considered to have been transient. In this instance, however, the physician should carefully monitor the child and repeat the thyroid function tests if any signs or symptoms of hypothyroidism develop. In this setting, the clinician should have a high index of suspicion of relapse. If the results of the levothyroxine withdrawal test are inconclusive, careful follow-up and subsequent testing will be necessary.
Since some more severely affected children may become clinically hypothyroid when treatment is discontinued for 30 days, an alternate approach is to reduce the replacement dose of levothyroxine by half during the 30-day trial period. If, after 30 days, the serum TSH is elevated above 20 mU/L, the diagnosis of permanent hypothyroidism is confirmed, and full replacement therapy should be resumed. However, if the serum TSH has not risen to greater than 20 mU/L, levothyroxine treatment should be discontinued for another 30-day trial period followed by repeat serum T4 and TSH testing.
The presence of concomitant medical conditions should be considered in certain clinical circumstances and, if present, appropriately treated (see PRECAUTIONS). ” Read the full PI here.
If you have a child with congenital hypothyroidism that is approaching age 3, I recommend talking very openly with your child’s pediatric endocrinologist about all of your concerns. Ask them what symptoms you should be on the lookout for during the trial and what the plan will be if you begin to notice those symptoms. For my boys at that age, the most common symptoms of hypothyroidism were sleepiness/lethargy (taking longer naps and sleeping longer at night), constipation and tearfulness (aka moodiness that was above normal preschool aged meltdowns). Others have noticed things like puffy face, nosebleeds, feeling cold frequently and having dry skin. Paying attention to the symptoms is an important part of the trial off thyroid medication.
For those of you about to enter the trial period, I wish you luck!
By Blythe Clifford aka Thyroid Mom