Endocrine Abstracts

Introduction: Pregnancy is a challenging time to maintain proper thyroid function in mothers and to provide sufficient thyroid hormones to the developing fetus. Micronutrient deficiencies are very frequent during gestation. So far only a few microelements are recommended as a routine supplementation and there is a gap in understanding the mutual relationship between multiple trace elements. The study aimed to verify the micronutrient status concerning thyroid parameters in the cohort of mothers and newborns.

Materials and methods: Women in the 3rd trimester of pregnancy (114), healthy and with autoimmune thyroiditis (AIT), together with their newborns (93) were recruited in the obstetric department before delivery in the tertiary reference Polish centre. Blood serum and spot urine samples from mothers and additionally neonatal cord blood were analysed. Microelement status was assessed in serum by Total Reflection X-ray Fluorescence analysis (on TXRF spectrometer S4 T-STAR). Additionally, thyroid parameters with antithyroid antibodies were measured in mother-newborn pairs and TSH concentrations from neonatal screening were analysed. The research was funded by the National Science Centre in Poland (2019/33/N/NZ5/02303) as PRELUDIUM-17 grant.

Results: More than half of mothers were poorly supplied in Ca, around 1/4 had Se and Zn shortages and 1/10 were deficient in Cu, where only 2.5% had insufficient Fe concentration. Median ioduria was 101 µg/l, which is below the WHO recommended value. Multinutrient formulas dedicated to pregnancy were taken by 68% of women. Maternal and neonatal micronutrients (Ca, Cu, Zn, Se) were adequately correlated with the strongest relation for Ca (r=0.5, P<0.001). Multiple correlations were also noticed among various trace elements in mothers and newborns, with the most prominent between Zn and Ca in mothers (r=0.78, P<0.001) and neonates (r=0.68, P<0.001). Maternal Ca, Fe and Se were related to ioduria. Additionally, Ca, Cu, Zn in mothers and Fe, Cu, Se in neonates correlated inversely with TSH screening values. Micronutrient supply was not different in AIT vs non-AIT women, although maternal Cu, Ca, Zn and neonatal Se, Fe, Zn correlated negatively with TRAb level.

Conclusions: Many pregnant women are at risk of health-relevant trace element deficiency, despite common supplementation of multinutrient preparations. Maternal supply may affect the newborn microelements status. Trace element screening and supplementation verification in pregnancy would be beneficial to mothers and newborns. Proper nutritional intake may improve thyroid parameters and decrease the concentration of thyroid antibodies. More studies on the mutual interplay between various microelements in pregnancy are warranted.