Subclinical hypothyroid, pregnancy and miscarriage

[Sazzle12345]

Hi

I am a long tome lurker and have read every post that I can find on this topic, but would be grateful for some Mumsnet wisdom.

By way of background, I have been pregnant 8 times and have one wonderful son. Pregnancy 1 and 2 were lost early (5/6) weeks. Pregnancy 3 was my son. Pregnancies 4-8 were also 3 x early losses and 2 later. In the 2 later losses I had early scans (due to my history) and all looked well until around 7 weeks when growth started to slow. They were both missed miscarriages, found at around 10 weeks but with the baby measuring 8+1.

I have had every test going, and have been seen by Prof Quenby in Coventry. I have / had chronic endometritis and this has been treated with antibiotics. Every other test was negative.

My theory for a while has been that my thyroid is playing a role. My test around a year ago was TSH 3.55 Ft4 13.9, so in range but possibly not ideal.

I am now pregnant again. As soon as I found out I had my bloods done, my TSH was 2.7 and Ft4 15.7, so again all normal.

Yesterday I had my first early scan, all looked good. I raised the thyroid issue be the consultant agreed to check again. Yesterday the result was TSH 4.36 and Ft4 13.8. So not great. There was 2 weeks between these tests and to my mind a significant rise.

I have been given 50mg levothyroxine which I have started today. The consultant (who specialises in recurrent pregnancy loss) said there is a lack of clinical evidence of benefit for subclinical hypothyroidism in pregnancy, but agreed it was worth a try and would do no harm.

With apologies for the long post, does anyone have any experience of this? My concern, given what I have read about thyroid meds, is that they take a long time to have any impact and therefore if my thyroid has played a part in my miscarriages, it will be too late this time. For the baby, I understand that it is the Ft4 that is relevant. Does that start to rise immediately on beginning the medication?

Can anyone provide any reassurance? Thank you

Can't speak for thyroxine in your particular pregnancy, but I know they have to increase the dosage really slowly. Is this the first time you have been offered thyroxine and was your thyroid under active prior to falling pregnant? My levels shot up to 7.8 in early pregnancy but are now back down to around 2, though I was 0.4 prior to falling pregnant. My consultant mentioned that anything between 3 and 4 was ok but not ideal, and that lower than 3 was safest. Your levels should come down quite quickly to the safe zone I would expect, but again I can only speak from my own experience having had an under active thyroid for 10 years. Sorry this is causing you so much anguish, I know it's bloody horrible x

Thyroxine is almost instant apparently

@Herecomestreble1 thank you for your reply.

I have never been diagnosed with a thyroid issue and any other blood tests I have had previously have shown similar levels - borderline hypo, but not quite.

The recurrent miscarriage consultant seemed very relaxed about it all. It was my suggestion that my levels be checked, and she agreed that if my TSH was over 2.5 she would prescribe.

I will just have to keep everything crossed that, to the extent my thyroid has been an issue with my miscarriages, I have caught it early enough to make a difference this time.