THE IMPACT OF MILD MATERNAL NUTRITION DEFICIENCY IN THE FETAL BRAIN - THE SWIDDICH STUDY

Cognitive and behavioural problems are common in children and early nutrition is a causal factor.

Our data infer that mild iodine and selenium deficiency is prevalent in Swedish pregnant women, as also observed worldwide.

These minerals are essential for thyroid function and moderate-severe deficiency has negative impact on pregnancy and fetal outcomes.

There is a lack of evidence on the effects of mild iodine and selenium deficiency during pregnancy, so there is an urgent need, both for the individual and society, to define cost-effective and safe interventions that can improve neurodevelopment on a population level. Combined supplements promoting thyroid function taken during pregnancy may help meet these needs.

This study is requested by the Iodine Global Network and the National Food Agency.We will evaluate in a double-blind randomised controlled trial of pregnant women (N=1264) and their children (N=788), whether a daily supplementation with iodine and selenium during pregnancy improves brain function in the child, in terms of cognitive function, psychomotor development and behaviour.

The effects on maternal iodine status, thyroid function and pregnancy outcomes will be investigated. In the children, psychomotor and cognition will be tested at 1.5, 3.5 (verbal IQ, primary outcome) and 7-years of age. We will also collect information on growth and morbidity. Through Formas support, 1070 women are recruited so far, and 3.5-year evaluations of children started in 2021.