Graves' disease specific symptoms

Graves disease behaves like any other form of hyperthyroidism. More specific features include

Exophthalmos: This is the telltale protuberance of eyes (usually both) that is seen in this condition
Thickening of skin usually affecting the legs giving a so-called orange peel (peau d’orange) look

Prevalence of Graves’ disease (Basedow’s disease) in pregnancy

It is estimated that Graves’ disease affect around 1 in every 500 pregnancies (0.2%)

Treatment for hyperthyroidism in pregnancy

There are two main types of medication that can be used in pregnancy. Both are considered safe.

Propylthiouracil (PTU) is preferred in North America and Carbimazole (Neo-Mercazole®) is used more in most of Europe. They are both very effective.

Both PTU and carbimazole cross the placenta. This is why just the optimal dose needs to be used to control the disease. Excessive doses have the potential of suppressing the developing thyroid gland of the fetus causing goiter.

Evidence shows that in optimal doses, these two drugs are quite safe for the baby.

The use of radioactive iodine during pregnancy

Radioactive iodine is one of the treament options in a non-pregnant state. It is never used during pregnancy. This can permanently destroy the fetal thyroid gland.

Surgery to treat an over-active thyroid in pregnancy

Surgery is an option. If medical treatment fails to control the hyperthyroidism, then partial resection of the thyroid gland may be undertaken. This is normally only considered after twenty weeks of gestation. It is unusual to resort to this treatment method during pregnancy.

Effect of good control of maternal hyperthyroidism on the baby

In cases where the hyperthyroidism was due to Graves' disease, there is still a risk that the baby will be affected, regardless of the level of control in the mother. At least 1 in 10 such babies are born with Graves' disease because of passage of the antibodies from mother to baby across the placenta.

The drugs suppress the production of the hormone but do not eliminate the rogue antibodies. However, the condition in the baby will be transient.

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Exophthalmos is specific for Graves' disease

The ‘staring eyes’ (exophthalmos) affecting one or, more commonly, both eyes, is a specific feature of Graves’ disease, the commonest thyroid disease seen in pregnancy