What are the dangers of breastfeeding from mothers with hyperthyroidism?

Hyperthyroidism is an endocrine disease. After suffering from hyperthyroidism, especially women who want to have children, they must actively seek treatment. Hyperthyroidism will directly affect women's fertility. Pregnant women with hyperthyroidism need to actively treat hyperthyroidism after giving birth, especially women who breastfeed their children. If the drugs used to treat hyperthyroidism, especially in large doses, are relatively large, breastfeeding must be stopped. Breastfeeding is harmful to the fetus.

The harm of breastfeeding from mothers with hyperthyroidism

Patients with hyperthyroidism often have their condition worsened after delivery, and need to increase the dose of anti-thyroid drugs. Mothers who need to continue taking medication or need to switch to radioactive iodine-131 treatment should not breastfeed. If the doctor believes that the mother's hyperthyroidism has been cured and she no longer needs to take medication, she can breastfeed.

For patients with hyperthyroidism who are treated with radioactive iodine-131, continuing to breastfeed will be harmful to the baby and should be absolutely prohibited.

Women with hyperthyroidism who are treated with medication usually need to continue taking antithyroid hormone drugs after delivery. If the mother's hyperthyroidism is severe and the medication dosage is high, she should not breastfeed.

If a lower dose is required to maintain normal thyroid function and breastfeeding is possible, the choice should be between propylthiouracil and methimazole. The concentration of propylthiouracil in breast milk is low, while the content of methimazole in breast milk is high, and it has a long duration of action, slow metabolism, and a longer duration. Therefore, propylthiouracil should be preferred.

There is no clear effect on breast-fed children if the dose is less than 30 mg of methimazole or 950 mg of propylthiouracil per day.

Early postnatal infant screening - 3 to 5 days after birth, a heel blood sample is taken for routine screening. Currently, items included in the screening scope in my country include congenital hypothyroidism (CH) and phenylketonuria. About 90% CH can be detected. If detected early, it is completely curable. However, if hypothyroidism is not discovered until the baby is over 6 weeks old, it will be too late to treat it.

When a newborn is born, umbilical cord blood should be collected to check thyroid function and related antibodies, and attention should be paid to checking the size of the thyroid gland and the presence of murmurs. Neonatal hyperthyroidism mostly occurs within a few days or a week after birth. The affected children may show symptoms such as enlarged thyroid, bulging or widened eyeballs, high skin temperature, crying, large appetite, frequent bowel movements, and poor weight gain. Severe cases are accompanied by symptoms of hyperthyroidism crisis such as high fever, rapid heart rate, and rapid breathing. When the thyroid is hypothyroid, the child often shows poor response, no crying, less food intake, delayed bowel movements, and poor weight gain.