The passage of thyroid hormones from the maternal circulation to the fetal circulation is important for normal fetal development. This Review discusses the changes in maternal and fetal thyroid hormone levels during pregnancy and the factors modulating transplacental thyroid hormone supply to the fetus, as well as pathological situations in which the placenta cannot optimize fetal thyroid hormone levels.
- Shiao Y Chan
- Elisavet Vasilopoulou
- Mark D Kilby
