Iodine deficiency in pregnancy along a concentration gradient is associated with increased severity of preeclampsia in rural Eastern Cape

[helvella]

I'm sure everyone who has ever been involved with pregnancy has heard about the dreaded pre-eclampsia. Just the thing to get midwives (and mothers-to-be) worrying. Would be rather excellent if this paper represents a significant step towards understand the issue.

2022 Feb 4;22(1):98.

doi: 10.1186/s12884-021-04356-6.

Iodine deficiency in pregnancy along a concentration gradient is associated with increased severity of preeclampsia in rural Eastern Cape, South Africa

Charles Bitamazire Businge 1 2 , Benjamin Longo-Mbenza 3 4 , Andre Pascal Kengne 5 6

Affiliations

• PMID: 35120491

• PMCID: PMC8815178

• DOI: 10.1186/s12884-021-04356-6

Abstract

Background: Preeclampsia is a leading cause of maternal mortality and morbidity in South Africa. Iodine deficiency in pregnancy, which is amenable to correction through iodine supplementation, has been reported to increase the risk of preeclampsia. However, the association of iodine nutrition status with preeclampsia in South Africa has not been studied.

Methods: We enrolled 51 randomly selected normotensive pregnant controls at term together with 51 consecutively selected cases of preeclampsia and 51 cases of severe preeclampsia/eclampsia, all in the third trimester, from Mthatha Regional and Nelson Mandela Academic Hospital in the Eastern Cape Province. Urinary iodine concentration (UIC), serum thyroid-stimulating hormone (TSH), triiodothyronine (FT3), thyroxine (FT4) and thyroglobulin (Tg) levels were compared between cases and controls.

Results: The respective chronological and gestational ages at enrolment for normotensive, preeclampsia and severe preeclampsia/eclampsia participants were: age 23, 24 and 19 years (p = 0.001), and gestational age 38, 34, and 35 weeks (p < 0.001). The median gravidity was 1 for all three groups. The median UIC, FT4, FT3 revealed a decreasing and Tg a rising trend with the severity of preeclampsia (p < 0.05). TSH had a non-significant rising trend (p > 0.05). The respective median values for normotensive, preeclampsia and severe preeclampsia/eclampsia participants were UIC 217.1, 127.7, and 98.8 μg/L; FT4 14.2, 13.7, and 12. pmol/L; FT3 4.8, 4.4, and 4.0 pmol//L; Tg 19.4, 21.4, and 32. Nine microgram per liter; TSH 2.3, 2.3, and 2.5 mIU/L. UIC < 100 μg/L, Tg > 16 μg/L and FT4 < 11.3 pmol/L were independent predictors of preeclampsia/eclampsia syndrome.

Conclusion: Women with severe preeclampsia/eclampsia had significantly low UIC and high Tg, suggesting protracted inadequate iodine intake. Inadequate iodine intake during pregnancy severe enough to cause elevated Tg and FT4 deficiency was associated with an increased risk of severe preeclampsia/eclampsia.

Full paper freely accessible here:

bmcpregnancychildbirth.biom...

[Sparklingsunshine]

I had severe pre eclampsia in my first pregnancy, I was in a very bad way and sadly I lost my son to stillbirth at just shy of 28 weeks. That was over 30 years ago and not much has improved in the intervening years.

Pre eclampsia and eclampsia are one of the leading causes of infant and maternal mortality even now and even in advanced first world health systems. It's a very sobering statistic. Anything that helps prevent or cure it is most welcome.

[helvella Administrator Thyroid UK in reply to Sparklingsunshine]

The way that the professions seem to be aware of the issue, but utterly ignorant as to why it happens, seems particularly cruel.

[shaws Administrator in reply to helvella]

It certainly is cruel if they ignore symptoms etc.

Many mothers-to-be don't know about signs/symptoms which can put both mother and baby in danger.

My mother lost her first and third baby but they were never forgotten. and I knew I had two other sisters.

[radd]

helvella,

Great post bringing attention to just one of the dangers of iodine deficiency during pregnancy, that is also happening here in the UK.

[helvella Administrator Thyroid UK in reply to radd]

I think the location and how life is there highlight the iodine gradient. I doubt that occurs much in the UK except in a few of us - such as people who grow a lot in their own gardens/allotments and are very close to the sea, or use seaweed as fertiliser.

(Used to apply to Jersey Royals - but I think they no longer use seaweed. And I have not been impressed by them for years. Connected? I don't know.)

So much of our food is transported, at the least within the UK.

[radd in reply to helvella]

helvella,

Yes re the Jersey Royals I read that somewhere too, which doesn't make sense because strong tides & perfect climate mean the seaweed grows close by in absolute abundance.

[helvella Administrator Thyroid UK in reply to radd]

What I vaguely remember is that using seaweed was very hard work - I think they used horses to collect and drag it up to the tatties.

Found this:

examinerlive.co.uk/lifestyl...

Bizarrely, in YorkshireLive.

[radd in reply to helvella]

You would think there was a mechanical way of collecting the seaweed and turning it into fertiliser, but now 'Grown under plastic' ...... Jersey BPA Royals 🤮.

[helvella Administrator Thyroid UK in reply to radd]

If they said that on their advertising and packaging, they'd probably lose an awful lot of sales.

In recent years, I have preferred Charlottes from Cornwall or Pembrokeshire, and Pembrokeshire Earlies.

[nightingale-56 in reply to helvella]

Thank you for all the information on Potatoes helvella . I have certainly not been very impressed with Jersey Royals for quite a few years now and will try some of those you mention here. I did have pre-eclampsia during my second pregnancy. My son has Panhypopituitarism.

[Londonist]

Is there a link between preeclampsia and hypothyroidism? I had PE at the very end of my pregnancy (thankfullly my son arrived safely), and also a PPH. My thyroid problems began after the birth although I wasn't diagnosed for several years.

[helvella Administrator Thyroid UK in reply to Londonist]

As an immediate reaction response:

If you were low in iodine, that could well mean you were hypothyroid - even if only marginally.

Imagine you were taking in just enough iodine when you were not pregnant. But, when you became pregnant, that was not enough. By the time you deliver, you go through pre-eclampsia, and after delivery you simply have not got enough iodine to keep going.

You continue being hypothyroid - possibly for years - as you never manage to overcome the deficiency.

However, that is just one "thought experiment". I'm sure there are other possibilities.

We generally say that jumping into taking iodine is a bad idea. As excess iodine causes its own set of problems. But it is always important to have enough iodine. And pregnancy does increase the need.

The UK is in a difficult place - possibly many are slightly iodine-deficient, but we are not seeing a huge number of cases of severe iodine deficiency.

Ideally, we'd all get tested and make decisions based on those results. But testing is relatively expensive and it simply does not get done.

[Londonist in reply to helvella]

Fascinating - and another example of how finely balanced all these things are. Thanks for the info.