23 weeks pregnant, Hashimoto's Normal TSH low Free T4...

[funinsun4]

Good Morning...my question relates to Hashimoto's, Pregnancy (currently 23 weeks), and thyroid levels...

Recent lab results

10/16/15:
TSH - 1.7
Free T3 - 2.7
Free T4 - .78 (low)

The Endocrinologist I see is suggesting I switch from Nature Throid to Synthroid since my T4 levels are low and out of the range and possible risks for the baby at having the T4 low like it is...she also suggested another option to maybe take a slightly higher dose of Nature Throid a couple days per week along with my regular dose on the other days to see if that helps but she said that may put me at risk for developing hyperthyroidism with the T3 in the Nature Throid and my T3 levels and my TSH already being at a good level. I am concerned about switching meds right now being 23 weeks pregnant but also want to do what's best for me and the baby. I've heard a lot of negative things about Synthroid and have done fine on Nature Throid with the exception of feeling faster heart rate an hour or two after taking it most mornings which I don't like...I'm afraid to change medications and have anxiety about medications in general as it is.

Previous labs were:

9/14/15
TSH - 2.97
Free T4 - .87
Total T3 - 125 (OB office didn't check free T3 just total...)

7/16/15
TSH - 2.39
Free T4 - .91
Free T3 - 3.2

[goolarra]

NT has a higher T3 content relative to T4 than our thyroids produce.  Depending on the source, NT is somewhere around 4-5 T4 to 1 T3.  Our thyroids produce something like 20 T4 to 1 T3.  So, with that much T3, it can be difficult for people to get their FT4 to a decent level without getting FT3 too high.  If you're concerned about your FT3 level going too high, why not add in a little synthetic T4?  You don't have to switch over entirely.  Keeping your current dose of NT and adding some T4 to it, if your doctor agrees, would accomplish raising your FT4 some.  

[goolarra]

If I were you, I'd try splitting your dose into two halves.  Half is usually taken first thing in the morning, and the other half late morning to early afternoon.  With less T3 taken in all at once, you'll get less of a jolt, which should help your elevated HR, and your FT3 level will be more consistent throughout the day.  If you do that, you just might be able to increase your NT without getting tachycardia.  

I'd be reluctant to make any big changes right now.  You've been doing well on NT, so it's probably worthwhile to stick with it.  I'd try splitting your pill, see if it reduces the tachycardia and then perhaps increase a little.  Right now, you have 3/4 grain going in all at once.  If you split the dose, you could increase to perhaps a whole grain, but you'd only be taking 1/2 grain at a time, so there'd be less of a spike in your FT3.    

[funinsun4]

I definitely prefer the idea of not making a huge change right now at 23 weeks but I am also concerned with my T4 being low and the risks associated with that. Since NDT has both T4 and T3 I'm not sure on the ratio and if increasing a little will bring back up my T4 to a safer range for the baby.

[goolarra]

Have you tried splitting your dose into two half doses, taking half in the morning and the other half late morning to early afternoon?  That would keep your FT3 level more even, and without such a spike might help your increased HR.

A TSH of 1.7 isn't too low.  Your FT3 is only 29% of range, which is low of the upper half of range target.  Do you have any hypo symptoms?

[funinsun4]

I haven't thought about splitting the dose just went with what the doctor prescribed...I don't really have any hypo symptoms more hyper symptoms it seems which is what confuses the doctor to begin with because of labs. I'm also curious if stopping the NDT to take Synthroid will have adverse reactions and overall what is best for this baby to be healthy.

[goolarra]

That's definitely another option.  I suggested adding T4 because you say you are doing well on NT, but have a faster heart rate after taking it.  However, that brings up another question:  Do you split your NT into two half doses?  How much NT are you taking?

[funinsun4]

I take 3/4 grain which is 48.75mg I believe of NDT...It is one small pill that I take before breakfast each morning.

[gimel]

Or as another viable option, why not just increase your daily dose of NatureThroid, which would raise both your T4 and T3 levels, since neither is at levels we usually recommend.  What daily dose of NT are you taking now?  

[funinsun4]

I am taking 3/4 grain of NDT now...I just wasn't sure how this all plays with my TSH already being lower now at 1.7 and if taking an increased daily NDT med will affect that as well...

[funinsun4]

I am afraid to be Hyperthyroid as I already experience what seems to be increased HR about 1-2 hours after taking my current NDT dose...

[goolarra]

What are the reference ranges on your FT3, FT4 and TT3?  Ranges vary lab to lab, so they have to come from your own lab report.  

Because NT has a relatively high T3 content and the half life of T3 is so short, you really don't accomplish a lot taking it a couple of times a week.  Has your doctor considered adding just a little Synthroid to your NT, rather than replacing it?  That would raise your FT4 a little.  Your FT3 might go up a little too, but probably not as much as if you increased NT.  

[funinsun4]

Thank you for the reply. The ranges are:

[funinsun4]

FT3: 2.0 - 4.4    FT4: .82 - 1.77   My Doctor didn't suggest the option of adding a little Synthroid but what you explain kind of makes sense and I will definitely mention it to her and see what she says. I dont think she's a huge NDT fan to begin with but she is leaving the decision up to me.