Thyroid UK
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Hypo and pregnant

Hello, so I've been struggling with under active thyroid since my daughter was born four years ago. Over the last year I started using NDT and followed a regime of supplements and lifestyle that had me feelng well. In fact better than ever. I feel I have been very lucky and now I am pregnant with my third child. I am a bit worried about managing my health through pregnancy.

I currently take 2 grains NDT daily

Vit C

B12 liquid with B complex

Flora vital




I have an appointment with GP on Friday to ask for blood tests. Can anyone give me advice as to what levels I should be checking now and throughout this pregnancy. Also, are the sups I currently take generally safe during pregnancy and are there others I may need.

Also, I have read up about increasing thyroid meds during pregnancy. The studies say to increase by 15% but at the moment I still feel really well and feel that would over medicate me right now.

I'd really like to hear others experiences of pregnancy and thyroid issues. thank you :)

9 Replies


Generally an increase is recommended but if you are still feeling well maybe this can be delayed a little.

It is essential to get your thyroid function tested, including TSH and free t4 (and t3if they will do it) as soon as possible and compare your t4 and t3 result to your last one where you were feeling well. If it has dropped a little you may wish to increase by a very small amount. If your doctor is knowledgeable on this subject, they should be able to advise. Your thyroid function should be checked at every trimester and your dose of ndt adjusted accordingly.

I would keep up with the B12 and B complex. The vitamin c should also be ok. I'm not sure about the others though.

I hope that helps

Carolyn x


Thank you Carolyn, I have an appointment on Friday and will get my levels checked as soon as possible after that.


I'm guessing you're in the states, but I the UK the advice is that for the first 12 weeks of pregnancy your TSH level is kept between 0.2-2.5. At this time your baby is completely dependant o you for thyroxine. It's recommended that you have your bloods checked every 4-6 weeks at this stage. After this time it's thyroid has developed and it will start to produce some of its own Thyroxine. At this stage your levels can be slightly higher.

I do t know enough about supplements to comment on that, but in the UK it's recommended to take a pregnancy vitamin containing folic acid and vitamin d For at least 12 weeks. After this time you can stop taking g folic acid as long as you have a healthy diet but you will need to take a seperated vitamin d supplement. (But like I said this advice is for the UK where we are in perpetual winter☺)

The only other advice is just general for any thyroid sufferers which is to take your meds, then wait for an hour before eating, and 3 hours before consuming foods high in calcium or iron as this can affect absorption.

hope that helps.


Thank you. I am in the UK but on the south coast so slightly more clement than other areas! That's good to learn about the thyroxine. I will see the doctor on Friday and may try a small increase before then. I'm already very careful about timings with my NDT so will keep up with that. I am taking a good quality pregnancy supplement that has both folic acid and bit D. Do you think this will be ok throughout the pregnancy or should I also start a separate vit D supplement? Thanks!


I really wouldn't suggest increasing any meds (especially thyroxine/hormones) or supplement without speaking to your doctor first the reason that it's adviced that levels are between 0.2-2.5 is because levels higher than this put you at greater risk of miscarriage. I dont want to scare you, but always be careful about self medicating, especially when pregnant. Xx


Thanks. It's really difficult to know what to do. I actually just moved doctors because I had a lovely supportive lady GP but she retired. So really hoping I can find another supportive GP! I left the last practise because it was so badly run I couldn't get appointments even for blood tests. I haven't had my levels checked for so long so I have no idea where I'm at just now. I felt the best I ever have just before getting pregnant so still having to work on how I feel. Hopefully things will be clearer after Friday!


Consider asking your GP/medic to keep a close eye on your iron levels, serum ferritin in particular. Floradix doesn't contain a great deal of iron, and making new babies is a big deal. You are absolutely right to be thinking about nutrient levels in pregnancy., your baby is fortunate. Watch your D levels and your B vitamin and iron levels in particular.. and keep watching your levels after you give birth, while you are breast feeding. And consider having a look through the debate on cord clamping, the timing of which has an effect on iron levels in the baby.

For example - this does NOT apply to you, please don't be scared, being pregnant can feel like the world is ganging up to terrify you - a recent study showed that women with severe sickness in the first trimester were more likely to have ADHD children. I just quote it because it shows how important nutrition is - low iron would be v likely to be a factor here. You are doing the right things.


Thank you. I was anaemic during my last two pregnancies so I think I will increase my iron intake (I was veggie previously but now eating meat so hopefully that will have a positive effect) and have seen in a few places now about vitamin D. It does feel a little scary this time as I didn't have (or perhaps wasn't aware of) my thyroid issues during the previous two. I feel so much more responsible for maintaing mine and my baby's health through this pregnancy. I don't feel that I can trust my body to 'just get on with it'.


You are v courageous to be going through pregnancy for a third time having endured anemia in your first two. Did you feel v v tired during them?

On D I think there are a number of studies now - here is a summary of one, the article is reviewed by a doctor.

Low D in pregnancy or babyhood may link to less dense bones in the child - they will be just as long, but less strong.

Keeping up iron levels in pregnancy is very, very, very important. With your history you have a very powerful weapon to make your midwife/dr monitor your levels closely. There is some evidence in animal studies that iron deficiency in the womb or in early life affects boys much more than girls. (That might just apply to rats, but my guess is that it probably applies to humans.) B vitamins too. I wish I had known all this in my own pregnancies.


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