Thyroid Disorders in Pregnancy

Thyroid conditions are common and important in pregnancy because thyroid hormones support the baby’s early development. With the right medication dose and regular monitoring, women with thyroid disorders usually have healthy pregnancies. The key is not to stop or change medication without advice.

Why the thyroid matters in pregnancy

The baby relies on the mother’s thyroid hormones in early pregnancy, and requirements often rise. Both an underactive (hypothyroid) and overactive (hyperthyroid) thyroid need attention, because untreated imbalance can affect mother and baby.

Hypothyroidism

This is the more common situation. Many women on thyroid medication need a dose increase in pregnancy, guided by blood tests (TSH). We check levels regularly and adjust the dose to keep them in the pregnancy-appropriate range.

Hyperthyroidism

An overactive thyroid is less common and needs careful, specialist-guided treatment, as both the condition and some medicines require balancing in pregnancy. We coordinate care closely in these cases.

Testing and the baby

Thyroid blood tests are done at booking for women at risk or with known disease, and repeated through pregnancy. With well-controlled levels, the outlook for the baby is usually excellent. Some women develop a temporary thyroid disturbance after delivery (postpartum thyroiditis), which we watch for.