Thyroid hormone availability during pregnancy and early life: determinants, interpretation and consequences

This thesis contains studies that investigates determinants of thyroid function during pregnancy and early life. We identified novel determinants such as angiogenic factors, known factors such as hCG and also clinical factors that were incorporated into a prediction model.
We also investigated how thyroid function during pregnancy is best interpreted. We demonstrate that TPO-antibody positivity may currently not be adequately defined and also show that total T4 is not a good marker for thyroid function assessment. Furthermore, we identified that suboptimal thyroid function during pregnancy is associated with premature delivery, pre-eclampsia and child neurocognition and brain morphology. Also, we show that the risk of adverse outcomes differs based on hCG concentrations and TPO-antibodies.