Although your body requires iodine, it doesn’t produce any on its own. You need to get enough through food or supplementation. Inadequate iodine levels are something you want to avoid. Your thyroid requires iodine to manage your metabolism and regulate your hormone production. If these processes are out of whack, you can experience problems like fatigue, depression, a low body temperature, weight gain, or goiter.
The Importance of Iodine During Pregnancy
For pregnant women, the situation is compounded. Iodine deficiency during pregnancy can cause long-lasting harm to the mother and create serious, if not fatal, consequences for the fetus; especially for brain development. Studies have shown that even mild iodine deficiency during pregnancy can be harmful to a child’s cognitive development.  Unfortunately, this damage is irreversible and often influences brain function.  
Iodine deficiency is not an issue pregnant, or thinking of becoming pregnant, women should be nonchalant about, the results can be serious and it’s more common than you think. In Belgium, for example, a study found thyroid disorders affected 1 in 6 pregnant women.  Monitoring and managing iodine intake during pregnancy can ensure the long-term health of the mother and child.
Looking beyond the nutritional requirement for this essential element, recent studies have taken a look to other impacts of iodine deficiency and their causes…
Iodine and Pre-Eclampsia
Unexpected seizures can happen during pregnancy, this is a very serious, life-threatening condition called eclampsia. High blood pressure and large amounts of protein in the urine can be a signal that eclampsia is next — and it cannot be ignored. Although eclampsia as a whole is a much larger topic than we’ll cover here, findings have suggested hypothyroidism during pregnancy influences the severity of pre-eclampsia. 
As a side note on the subject of pre-eclampsia… another study revealed that thyroid hormones and selenium did not change the result of pre-eclampsia. However, it did indicate a reduction in both miscarriages and preterm births, and fewer occurrences of post-partum thyroiditis in women who took selenium. 
Polybrominated Diphenyl Ethers (PBDE’s)
While the term may not be familiar, it is very likely you have been over-exposed to these toxic chemicals. PBDEs were used (until recently) as a flame retardant and have been found in the tissue of almost every North American! Feeling violated? You should, because they are connected to maternal thyroid levels.
PBDE’s have been found to play a role in the amount of thyroid hormone in the umbilical cord. In animal models, PBDE’s have been shown to reduce levels of thyroxine (one of the two important thyroid hormones). While human studies have produced less clear results, the nature of this contamination suggests monitoring iodine levels to protect thyroid health. 
Iodine Deficiency and Obesity During Pregnancy
Low thyroxine levels have been found in women with increased body weight. In pregnant women, obesity has been identified as a risk factor which may lead to thyroid dysfunction. A recent study found that obese women, already at risk of iodine deficiency, have a substantially higher risk of hypothyroxinaemia. This is especially true during the first trimester and can lead to developmental issues. 
Iodine Intake During the Last Trimester
Supporting healthy iodine levels during the first two trimesters is imperative to support normal fetal neural development for the fetus and healthy post-partum thyroid function for the mother. The third trimester is just as important. A 2013 study found that iodine consumption during the third trimester had a positive correlation with adequate thyroid hormones at the time of delivery. 
Supplementing With Iodine
The consequences of improper nutrition is the sort of topic that can keep pregnant women awake at night. Improper neural development isn’t the sort of thing any expecting mother is hoping for. But, it’s important to know that iodine levels are within your control and can be managed through dietary and supplemental iodine. There are a few forms of iodine available, I always recommend nascent iodine.
Is iodine intake something you are, or were, on top of during your pregnancy? Please leave a comment below and share your experience with us. It’d be great to get some feedback on the subject!
- Dr. Edward F. Group III, DC, ND, DACBN, DCBCN, DABFM
- Mild iodine deficiency in pregnancy harms child’s development. Nurs Stand. 2013 Aug 21;27(51):16.
- Pearce EN. Monitoring and effects of iodine deficiency in pregnancy: still an unsolved problem? Eur J Clin Nutr. 2013 May;67(5):481-4. doi: 10.1038/ejcn.2012.215. Epub 2013 Jan 16.
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- Reid SM, Middleton P, Cossich MC, Crowther CA, Bain E. Interventions for clinical and subclinical hypothyroidism pre-pregnancy and during pregnancy. Cochrane Database Syst Rev. 2013 May 31;5:CD007752. doi: 10.1002/14651858.CD007752.pub3.
- Chevrier J. Invited commentary: maternal plasma polybrominated diphenyl ethers and thyroid hormones–challenges and opportunities. Am J Epidemiol. 2013 Sep 1;178(5):714-9. doi: 10.1093/aje/kwt138. Epub 2013 Aug 7.
- Gowachirapant S, Melse-Boonstra A, Winichagoon P, Zimmermann MB. Overweight increases risk of first trimester hypothyroxinaemia in iodine-deficient pregnant women. Matern Child Nutr. 2013 Aug 13. doi: 10.1111/mcn.12040.
- Velasco I, Martin J, Gallego M, Gutierrez-Repiso C, Santiago P, Lopez-Siguero JP, Gonzalez Mesa E, Herrera Peral J, Perez V, Garcia-Fuentes E, Soriguer-Escofet F. Maternal-fetal thyroid function at the time of birth and its relation with iodine intake. Thyroid. 2013 Jun 13.