Journal Article

Determinants of placental iodine concentrations in a mild-to-moderate iodine-deficient population: an ENVIRONAGE cohort study

Nawrot, Tim S., Cox, Bianca, Ruttens, Ann, Roels, Harry A., Neven, Kristof Y., Vrijens, Karen, Plusquin, Michelle

2020

Overview

Background Iodine is an essential trace element for the production of thyroid hormones, and plays a key role during the gestational period for optimal foetal growth and (neuro-)development. To this day, iodine deficiency remains a global burden. Previous studies indicate that the placenta can store iodine in a concentration-dependent manner and serve as a long-term storage supply, but studies on the determinants of long-term placental iodine load are limited. Methods The placental iodine concentrations were determined for 462 mother-neonate pairs from the ENVIRONAGE birth cohort (Limburg, Belgium). Sociodemographic and clinical variables were obtained from questionnaires and medical files. Determinants of placental iodine concentration were identified using stepwise multiple regression procedures ( p value < 0.15). The biological significance of our findings was investigated by measuring the plasma thyroid hormones in maternal and cord blood of 378 participants. Results A higher pre-pregnancy BMI, higher gestational weight gain, and alcohol consumption during pregnancy were linked with lower placental iodine storage. Multi-vitamin supplementation during pregnancy and longer gestation were associated with higher levels of placental iodine. Children born during the winter period had on average higher placental iodine levels. Besides, we found a significant positive time trend for placental iodine load over the study period 2013 to 2017. Lastly, we observed positive associations of both the maternal and cord plasma thyroxine concentrations with placental iodine load, emphasizing their biological link. Conclusions This study identified some determinants likely presenting a risk of reduced iodine storage during the gestational period of life. Future studies should elucidate the effects of lower placental iodine load on neonatal health, and health later in life.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Alcohol / Alcoholic beverages / Belgium / Biomedical and Life Sciences / Biomedicine / BMI / Child / Cohort analysis / Cohort Studies / Computational Modelling and Epidemiology / Cord blood / Diagnosis / Education / Ethnicity / Female / Fetal development / Fruits / Gestation / Gestational age / Grandparents / Health aspects / Hormones / Humans / Hypertension / Infant, Newborn / Iodine / Iodine deficiency diseases / Medicine/Public Health / Mothers / Neonates / Parent educational background / Patient outcomes / Placenta / Population studies / Pregnancy / Prenatal influences / Questionnaires / Regression analysis / Statistical analysis / Supplements / Thyroid gland / Thyroid Hormones / Thyroxine / Trace elements / Variables / Weight gain