Can pregnant women be treated with radioactive iodine when having basedow?

This is an automatically translated article.

The article is professionally consulted by Master, Doctor Tran Lam Khoa - Department of Obstetrics and Gynecology - Vinmec Central Park International General Hospital.
Radioiodine therapy is effectively used in patients with Graves' disease and thyroid cancer. But for pregnant women, this method is not recommended because this chemical can destroy the thyroid gland of the fetus (hypothyroidism), as well as slow down intellectual development and increase the risk of malignancy in the newborn. .

1. Graves' disease in pregnant women

Pregnancy can cause a number of important physiological and hormonal changes that alter thyroid function. These changes will be tested through thyroid function during pregnancy. This disease is influenced by two main hormones: estrogen and chorionic gonadotropin (HCG) - hormones used for rapid pregnancy test. HCG can be elevated during the first 3 months leading to lower TSH. When this happens, the TSH will decrease slightly during the first 3 months and then return to normal throughout the pregnancy. Estrogen increases the serum levels of thyroid hormone-binding proteins, making the blood hormone energetic > 99% of the thyroid hormone in the blood bound to these proteins.
Thyroid gland is functioning normally if TSH and T4 are within the normal range of pregnancy. The thyroid gland can change size during pregnancy. However, it only concerns women living in iodine-deficient areas.
Therefore, the most common cause of hyperthyroidism in pregnant women is Graves' disease aka Basedow's disease. High levels of HCG can cause transient hyperthyroidism in early pregnancy.

2. Radioiodine treatment

Iodine is normally one of the basic nutrients that the body needs and the source of iodine for the body is through food. Thyroid gland - gland in the neck that uses iodine to make hormones that perform basic bodily functions such as growth and physical development. However, the iodine used in another form is radioactive iodine, which has a high energy level that can be harmful to the body.
Iodine is established into two forms of radioactive iodine commonly used in patients with thyroid disease: I-123 (harmless to thyroid cells) and I-131 (destroys thyroid cells). The radiation emitted from each of these forms of iodine can be detected outside the patient to obtain information on thyroid function and image the size and position of thyroid tissues. Radioiodine treatment is quite safe for people who already have a seafood allergy or X-ray contrast agent, because the reaction is a compound containing iodine, not iodine alone.

2.1. The action of radioactive iodine

When a patient receives a dose of radioactive iodine in liquid capsule form or intravenously, the thyroid gland absorbs all of it. A few hours later, a special scanner will give an image of where the radiation has passed. Parts of the thyroid gland that are less radioactive than the average person may be due to cancer. Furthermore, radioactive iodine can show whether cancer has spread beyond the thyroid gland. Therefore, this method will help the doctor recognize the condition of a lump in the neck (thyroid cancer).

2.2. Thyroid Cancer

Radioactive iodine can destroy the cells that make up the thyroid gland and thyroid cancer. If thyroid cancer has spread to other parts of the body, radioactive iodine can also attack those sites. The benefit of using liquid radioactive iodine is that the radiation will not affect the rest of the body. Because the thyroid cells have absorbed all this compound. After receiving a dose of radioactive iodine, you may give off radiation for a while. Therefore, you will be isolated in the hospital for a few days. And some possible side effects include: neck pain, upset stomach or dry mouth. Radiation can also affect sperm count in men as well as the ovaries in women.
If you have Graves' disease, your thyroid gland makes too much hormone. Radioactive iodine is the most common treatment for Graves' disease. Medications or surgical methods may also be selected and based on the severity of the disease.
In addition, radioactive iodine is also used in the treatment of cervical cancer, uterine cancer and eye cancer. Radioactive iodine treats eye cancers that are ocular malignancies or intraocular malignancies.

3. Risks of radioactive iodine treatment

In general, radioactive iodine therapy is a safe and effective treatment for thyroid disorders. Hypothyroidism is a common side effect of radioactive iodine treatment for hyperthyroidism and is commonly seen after radioactive iodine treatment for thyroid cancer. This condition is easily treated with thyroid hormone replacement.
Some studies show that a slight increase in thyroid cancer may be seen after radioactive iodine treatment for hyperthyroidism. For example, loss of taste and dry mouth are caused by damage to the salivary glands. At present, the use of lemon or vitamin C or sour stimulants to potentially reduce salivary gland exposure to radioactive iodine treatment remains unclear. Therefore, if you use this method, you should discuss it with your doctor.
Radioiodine treatment, whether I-123 or I-131, is not indicated for pregnant or lactating women. Because the baby will probably receive radioactive milk (the breast is the site of radioactive iodine concentration). If treated with this method, breast-feeding should be discontinued at least 6 weeks prior to I-131 therapy and breastfeeding should not be resumed after treatment. You should not become pregnant for at least 6 months after treatment to ensure that thyroid hormone levels are normal and stable because this treatment exposes the ovaries to radiation.

Vinmec International General Hospital is the address for examination, treatment and prevention of diseases, including Obstetrics and Gynecology. When performing the examination process at Vinmec, customers will be welcomed and used modern facilities and equipment along with perfect medical services under the guidance and advice of experts. Good doctors, well-trained both at home and abroad. Especially, pregnant women who use the package maternity service will be monitored, examined and detected early on abnormalities of the mother and fetus so that they can have a timely examination and treatment direction.
Master, Doctor Tran Lam Khoa is trained and used to specialize in fetal medicine and prenatal diagnosis at Necker Hospital - Prenatal diagnosis center - Fetal intervention and treatment center France's largest. This is also the place where difficult and complicated diseases are concentrated with the world's leading professors of fetal medicine and fetal intervention. Currently, Doctor Khoa is working at Vinmec Central Park International General Hospital, he will directly diagnose, treat, and intervene in fetuses to bring healthy babies and bring happiness to parents. future mother.
References: webmd.com, thyroid.org, ncbi.nlm.nih.gov

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