Pregnant and Thyroid Tests - Can anyone interpret?

[storm1234567]

Hi all,

I wonder if anyone can help. I am 24 weeks pregnant and was sent for a thyroid test as I have a history of being borderline low.

Results just came back and are as follows:

Serum TSH 1.66 mu/L

Serum free triiodthyronine 3.2 pmol/L

Serum free thyroxine 10.7 pmol/L

I am worried about the last result (T4 i think?). Does this seem excessively low? I am worried about how this might be affecting my baby. I don't know anything about these tests and have not had a call yet from the dr/midwife. Can anyone give me any feedback on these results?

[storm1234567]

For reference, normal range of T4 is 11.1-22pmol/L, TSH is 0.27-4.2mu/L and T3 is 3.1-6.8 pmol/L

[SlowDragon Administrator]

Was test done early morning, ideally around 9am for highest TSH

What vitamin supplements are you currently taking

You need referral to endocrinologist

Your TSH has remained low despite very low Ft4 and Ft3

This suggests central hypothyroidism

Important to get Vitamin D, folate, Ferritin and B12 levels tested

Were thyroid levels tested earlier in pregnancy

You pregnancy is far enough on now for your baby to have developed it’s own thyroid and baby should be making own hormones

[storm1234567 in reply to SlowDragon]

Thanks for your reply. Test was done in the afternoon actually, around 3.30. What is it that Vitamin D, folate, Ferritin and B12 levels will tell me?

They didn't test earlier in pregnancy sadly, so I have no frame of reference, but I do know in recent years my results have all been normal.

I take a pregnancy multivitamin that contains:

Vitamin C (Magnesium and Calcium Ascorbate) 200mg 250

Potassium (citrate) 48mg 2.4

Choline (bitartrate) 50mg

Iron (bisglycinate) 20mg 142

Natural Beta Carotene/Carotenoid Mix (D.Salina) providing 5mg

Beta Carotene 5mg

Cryptoxanthin 39µg

Alpha Carotene 158µg

Zeaxanthin 32µg

Lutein 25µg

Zinc (Citrate) 10mg 100

Inositol 25mg

Silica dioxide 20mg

Selenium (selenomethionine) 55µg 100

Vitamin B3 (nicotinamide) 13mg 81.2

Manganese (bisglycinate) 2mg 100

Boron (sodium borate) 1mg

Vitamin B5 (calcium pantothenate) 6mg 100

Vitamin B6 (pyridoxine HCI) 2.5mg 178

Copper (citrate) 1mg 100

Vitamin B12 (Adenosylcobalamin and Methylcobalamin) 2.5µg 100

Vitamin B1 (thiamine HCI) 1.4mg 127

Vitamin B2 (riboflavin) 1.6mg 114

Folic acid 400µg 200

Chromium (picolinate) 50µg 125

Vitamin D3 (400iu) 10µg 200

Iodine (potassium iodide) 150µg 100

Molybdenum (ammonium molybdate) 50µg 100

Vitamin K1 50µg 66

Biotin 30µg 60

Calcium (ascorbate and citrate) 51mg 6.4

Magnesium (from Magnesium Ascorbate and Citrate) 36mg 9.6

I am really worried ☹️

[HealthStarDust in reply to storm1234567]

“Biotin 30µg 60”

It is said on here that before testing all biotin products should be stopped for 7 days before. Elsewhere on the internet it is recommend 2 weeks. There’s some arguments around how much is consumed before it affects tests.

As someone else has pointed out, your baby will be making its own thyroid now and as your pregnancy has come along this far, it’s likely to be OK.

[SlowDragon Administrator in reply to storm1234567]

TSH would have been higher if tested at 9am

Request thyroid retested early morning including thyroid antibodies, vitamin D, folate, ferritin and B12

Stop vitamin supplement 3 days before test as contains biotin

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

Only do private testing early Monday or Tuesday morning. 

Link about thyroid blood tests

thyroiduk.org/getting-a-dia...

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

Symptoms of hypothyroidism 

thyroiduk.org/wp-content/up...

Tips on how to do DIY finger prick test 

healthunlocked.com/thyroidu...

Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee 

[HealthStarDust]

thyroid.org/hypothyroidism-...

apps.nhslothian.scot/refhel...

See above links on pregnancy and thyroid. Includes trimester specific ranges too.

I hope that’s helpful.

[storm1234567]

Thank you both. Verdict from GP seems to be that this isn’t very out of range for « for me » as T4 has been bouncing in and out of the normal window for the last decade - and that as I don’t have symptoms so to speak, treatment doesn’t seem necessary at this stage. It also seems clear from various sources online that the « normal » t4 range gets progressively a a bit lower during pregnancy, so hopefully it will return to normal once I have given birth.

Thanks for your input. Getting test results at night really isn’t helpful for peace of mind and sleep!

[humanbean]

I am 24 weeks pregnant and was sent for a thyroid test as I have a history of being borderline low.

From this link :

niddk.nih.gov/health-inform...

What role do thyroid hormones play in pregnancy?

Thyroid hormones are crucial for normal development of your baby’s brain and nervous system. During the first trimester—the first 3 months of pregnancy—your baby depends on your supply of thyroid hormone, which comes through the placenta. At around 12 weeks, your baby’s thyroid starts to work on its own, but it doesn’t make enough thyroid hormone until 18 to 20 weeks of pregnancy.