Thyroid Hormone Levels

[nanasmom]

Not sure where to post this but being I am trying for a homebirth, I figured I would try here.

Can anyone shed some light on what this means:
TSH levels are normal
T3 levels are low
T4 levels are high

I ask because I just has an appointment with my midwife and this showed up in my results. She mentioned that this can possibly be the reason the baby is on the bigger side. She did not seem very concerned, but I don't want anything ruining my chances for HBAC and force me to deliver in the hospital. I am going for a follow up ultrasound tomorrow because my fluid has been a bit high and she wants me to mention the thyroid results to the doctor as we would be transferring there should an issue come up. I know his stance on HBACs already and he used all the usual scare tactics when I met with him last time. I just need clarification on the thyroid results before I see him tomorrow, so I can seem somewhat educated about this when he tries to somehow tie this into why I should not have a HBAC.

Thank you in advance!

[Paige, CPM]

When I have had clients with thyroid concerns they have always had concurrent care with endocrinologists.

Once I had a client who had no insurance and I had to do all the testing TSH T3 T4, I did research online to find out most of the info so I was well prepared when I consulted with an ob over the phone. The OB said she did not really deal with that and that she always referred anything suspicious to her Maternal Fetal Specialist. When I called him he was able to confirm what I had found out about her results and offered to write her a RX w/out seeing her if I faxed him the labwork...nice guy!

Anyway, I would say that a thyroid condition does not at all preclude you from a homebirth if it is being managed by someone qualified, like an endo, perinatologist or maternal fetal specialist. I would not necessarily trust an ob to interpret the results...TSH being wnl does not mean all is ok depending upon the other results (T3 and T4) if it is on the higher or lower end of normal. I am sorry I can not remember the specifics off-hand as this was a few years ago but I would recommend on-line research and a consult with an endocrinologist.

Good luck and let us know how it goes.

[autumnday]

My first question would be what prompted the thyroid test in the first place? I don't believe that is routine in prenatal care. Are you showing symptoms of a thyroid condition?

There are many things that result can mean, and it may be nothing.

First, some care providers and labs use different ranges for pregnancy since estrogen can affect thyroid hormones, so checking with someone who knows the prenatal ranges may elicit different results.

Second, your TSH may not necessarily be normal, the upper limit has been lowered by the American Association of Clinical Endocrinologists, but many labs and health care providers have not lowered their limits. The new lower limit is usually listed at around 3.00 mIU/L, and may even be lowered to 2.5 in the future. Many labs still have 5.0 as the upper limit for normal, so you may need to get the actual numbers to see if your TSH is indeed normal.

Third, it's not clear whether it's the free or total form of the hormone that is high/low, which can make a big difference in the interpretation of the results. Also, many things can affect the conversion of T4 to T3 (the more active form) including stress (cortisol), medications, diet, etc.

If you or your midwife have concerns, it is best to consult with an endocrinologist as Paige said, especially if you are showing signs of thyroid problems.

[triony]

Originally Posted by autumnday

My first question would be what prompted the thyroid test in the first place? I don't believe that is routine in prenatal care. Are you showing symptoms of a thyroid condition?

My OB (before I started seeing a MW) did run a thyroid test as part of standard "pre-conception" checkup. Thank goodness she did, because I finally figured out why I had been feeling so terrible off and on for years.

Originally Posted by autumnday

Second, your TSH may not necessarily be normal, the upper limit has been lowered by the American Association of Clinical Endocrinologists, but many labs and health care providers have not lowered their limits. The new lower limit is usually listed at around 3.00 mIU/L, and may even be lowered to 2.5 in the future. Many labs still have 5.0 as the upper limit for normal, so you may need to get the actual numbers to see if your TSH is indeed normal.

ABSOLUTELY!!!! This is so important to understand.

Originally Posted by autumnday

If you or your midwife have concerns, it is best to consult with an endocrinologist as Paige said, especially if you are showing signs of thyroid problems.

I wholeheartedly agree. I LOVE my endocrinologist. Please see one ASAP if you are able.
A study was done ages ago that showed that low thyroid in preganancy can affect the fetus' IQ. (And who knows what else) They can't repeat a study like that in humans for ethical reasons, but one of the things they test for immediately after birth is whether the baby's thyroid is functioning normally. If not it can have severe effect on the baby as it grows. Makes sense to me that this would be true for in utero as well.