Underactive thyroid

[LHMB]

I'm 26 weeks and have been sent appointments for growth scans at 28 weeks, 32, and 36 weeks, they've increased my levothyroxine as well. I was reading online that having an underactive thyroid can cause the baby to have birth defects and I'm pretty worried now. Someone told me as well that you shouldn't get pregnant with an underactive thyroid. Anyone any advice?

I had my thyroxine upped from 100mcg to 125 mcg during pregnancy,all was fine.Ds is 5 now. try not to worry

I have an underactive thyroid and am on my third pregnancy. My understanding is that provided your levels are well managed (they should be tested at least once per trimester after which your medication will be adjusted, under the supervision of an endocrinology consultant) then there is no risk to baby.

Being pregnant increases your thyroxine needs, so it is normal for your dose to be increased. The main issue is that poorly managed thyroid can make it hard to get pregnant in the first place. I have never had growth scans due to hypothyroidism, is this because your levels are unstable? Do you know your blood results?

I have 4 very healthy sons, and have been hypothyroid my whole life. They do monitor you more closely but I’ve never been told I might have babies with birth defects or any other issues, I think there are issues for some women trying to get pregnant but certainly never been told anything else. My sister is also hypo but due to having her thyroid removed and has a baby boy and 2 other kids.
Speak to your consultant next time you’re there and ask questions, wishing you a healthy rest of pregnancy

Thanks for replying, mine has also been increased from 100mg to 125mg. No I don't know, I have fortnightly appointments at the hospital with thryroid consultant and they test my blood every time, they never tell me the results, just if the dose needs adjusting. They said you need growth scans when you have an underactive thyroid, and my midwife said it can affect the placenta and the baby can measure small

My baby was 8lb 10!

Thank you

Think my hospital has been a bit amiss as no one has even mentioned my thyroid! I've had an underactive thyroid for 5 years, this is my first pregnancy and had my dose upped twice (75 to 125) - that was because of my GP not the midwives / antenatal clinic. I'm 37 weeks tomorrow - should I push for closer monitoring or just leave it as it's so close to the end now?

Also sorry @LHMB for hijacking your thread!

@31SunshineSophia no problem! I guess you could mention it to your midwife

Hi there,
My mum didn’t know she had an under active thyroid. She had 12 miscarriages before she had my brother due to this condition having never been diagnosed. He weighed less than 2lb. This was 55 years ago. He survived which was unusual as he was so small. He is a perfectly functional member of society. She then had me two yrs later after being diagnosed with an under active thyroid and being prescribed thyroxine. I was 6lb in weight. Perfectly normal apart from an under active thyroid. I am a primary school teacher. I had trouble conceiving for 5 years until it was discovered that my prolactin levels were high due to the fact that my t4 levels were still low due to under treatment. My dose of thyroxine was doubled and I became pregnant within 3 months. I have had three children - all normal weight and without thyroid problems. I do not think that this condition affects babies - saying that some babies are born without thyroid function. The heel prick test picks this up shortly after being born. Babies who don’t receive thyroid replacement have learning difficulties - they were once classed as ‘cretins’ (not a nice term). The only problem I have had concerning my thyroid condition was the ‘infertility’ due to not having enough hormone in my body due to being on insufficient thyroxine dosage. Prolactin is high when t4 levels are low. Prolactin is produced in larger amounts when breastfeeding and stops further pregnancies. When baby is demanding less milk (weaning) prolactin levels fall. This accounts for lots of pregnancies in mums around the time when their babies are approx. 8 months old as some women don’t realise they are fertile whilst breastfeeding and prolactin levels are high. When breast milk production falls, prolactin levels fall and fertility is regained. My high prolactin levels due to insufficient thyroxine kept me infertile for five years. I think these levels are checked routinely now if women are failing to conceive. An under active thyroid is a very common condition - I know many women with this condition who have children, grandchildren and great grandchildren - all perfectly healthy. If you have any concerns please ask your midwife, GP, consultant - they will reassure you. Please don’t worry - it’s not an issue for you to fret over.

I have an underactive thyroid with antibodies and am consultant led but as it’s well controlled by my GP (he tests every 4 weeks) all she does is review the results. I was told I wouldn’t need extra growth scans but was given a baby alert as my antibodies have the potential to cause hypothyroidism in the baby.

Suggest you ask your mw / gp why your thyroid levels are not being tested regularly - this is something they may require you to arrange.

Thanks - I'm defo going to mention it at my next midwife appointment

That's so interesting @NannyAnnieKnitsKnickers I hadn't heard of the link between hypothyroidism and prolactin levels before