A 2025 study from University College Cork (UCC) has found that 60% of pregnant women had suboptimal iodine status, a concerning figure given iodine’s central role in reproductive and foetal health. The findings, published in the European Journal of Nutrition, assessed urinary iodine concentration (UIC) data from over 1,500 first-time mothers attending Cork University Maternity Hospital.¹

The average UIC was 125 µg/L, falling below the World Health Organization’s recommended threshold of ≥150 µg/L during pregnancy, suggesting iodine insufficiency.² While two-thirds of participants reported using a pregnancy supplement, the majority remained below optimal levels highlighting gaps in dosage, formulation, or dietary intake.

 

The Role of Iodine in Reproductive Health

Iodine is a key component of the thyroid hormones triiodothyronine (T3) and thyroxine (T4), which regulate metabolism and are essential for reproductive health. Even mild iodine deficiency can impair thyroid function, which has been linked to reduced fertility, irregular menstrual cycles, and a higher risk of miscarriage.

Thyroid hormones closely interact with the hypothalamic-pituitary-gonadal (HPG) axis, which governs ovulation, menstrual regulation, and sex hormone production. When iodine intake is insufficient, thyroid hormone production is compromised, disrupting these delicate hormonal interactions and potentially impairing conception.

 

Critical in Early Pregnancy

During the first trimester, the developing foetus relies entirely on maternal thyroid hormones to support the formation of the brain and spinal cord. If the mother is iodine deficient, this demand may not be met, putting early development at risk. By the time pregnancy is confirmed, organogenesis (organ formation) is already well underway, making preconception iodine status critically important.

Unlike some nutrients, iodine is not stored in large reserves. It must be consumed regularly via diet or supplementation to maintain adequate levels. Building iodine stores before conception supports ovulatory health, hormonal balance, and the body’s ability to respond to the increased physiological demands of early pregnancy.

 

How Proceive® Supports Iodine Needs

Both Proceive® Conception and Pregnancy formulations contain iodine, supporting the production of maternal thyroid hormones and helping to meet the demands of both reproductive health and foetal development.

Proceive® also delivers a wide spectrum of high-strength, bioavailable nutrients, tailored for the pre-conception period and each trimester of pregnancy. With no fillers or unnecessary additives, Proceive® offers a considered, high-quality option for women planning or expecting a baby.

 

Conclusion

The UCC findings highlight a significant public health gap: iodine deficiency continues to affect a majority of pregnant women, despite supplement use. For healthcare professionals supporting patients through preconception and pregnancy, ensuring adequate iodine intake through diet and supplementation remains a key step in optimising pregnancy outcomes.

 

References

1. UCC News, 2025. 60% of pregnant women show signs of iodine deficiency. https://www.ucc.ie/en/news/2025/60-of-pregnant-women-in-irish-study-show-signs-of-iodine-deficiency-ucc-research-finds.html
2. WHO, 2007. Assessment of Iodine Deficiency Disorders and Monitoring their Elimination. WHO/NHD/01.1
3. Zimmermann MB. (2009). Iodine deficiency. Endocrine Reviews, 30(4), 376–408.
4. Bath SC et al. (2013). Maternal iodine status and IQ of offspring: a UK cohort study. The Lancet, 382(9889), 331–337.
5. Bath SC et al. (2017). Iodine deficiency in the UK – A growing concern? Nutrition Bulletin, 42, 206–216.
6. Glinoer D. (2001). Pregnancy and iodine. Thyroid, 11(5), 471–481.
7. WHO/UNICEF/ICCIDD (2007). Iodine deficiency in pregnancy: public health strategies.
8. EFSA Panel on Dietetic Products (2014). Scientific Opinion on Dietary Reference Values for Iodine. EFSA Journal 2014;12(10):3660.