The importance of iodine in pregnancy
An Australian study of neonatal TSH levels suggests that iodine deficiency is becoming more common.1 As iodine deficiency and thyroid disorders are particularly important during pregnancy, Therapeutic Guidelines: Endocrinology offers advice on these problems.
Mild iodine deficiency in pregnancy can limit a child’s future intelligence. It can also cause maternal goitre. The recommended daily intake of iodine is 250 mcg during pregnancy and lactation, and supplements may be needed.
Maternal thyroxine is critical for fetal brain development. Even subclinical hypothyroidism has been associated with miscarriage and preterm labour.
Women with hypothyroidism need their thyroxine therapy to be optimal during pregnancy, and thyroxine requirements will increase as the pregnancy progresses.
When monitoring TSH, remember the normal range in the first trimester is lower than in nonpregnant women.