Hashimoto's syndrome

Hashimoto's syndrome that is untreated or poorly treated can cause problems for both a pregnant woman and a developing fetus. It is recommended that affected women plan their pregnancies and make sure that thyroid function is well-controlled before becoming pregnant. Women with Hashimoto's syndrome should consult with their health care providers prior to pregnancy.

Potential complications of an underactive thyroid in a pregnant mother may include preeclampsia, anemia, miscarriage, placental abruption, and/or postpartum bleeding.

A developing fetus' brain and nervous system need thyroid hormone to develop normally. During the first trimester, the fetus depends on the mother’s supply of thyroid hormone. Effects of a mother's underactive thyroid on a fetus may include preterm birth, low birth weight, birth defects, thyroid problems, and/or stillbirth.^[1]

Women with Hashimoto's syndrome may need to see their obstetrician or perinatologist, and an endocrinologist. The goal of treatment is to normalize maternal levels of thyroid hormones. Thyroid hormone replacement using synthetic thyroxine (such as levothyroxine) is both safe and necessary for the health of the mother and developing fetus. Women with Hashimoto's syndrome who are planning to become pregnant should speak with their health care provider prior to pregnancy to make sure their hypothyroidism is corrected. Women who are being treated usually need a higher dose to maintain normal thyroid function during the pregnancy, and there are specific ranges of ideal hormone levels for each trimester of pregnancy. Therefore, it is recommended that thyroid function be checked often during pregnancy so adjustments to the dosage can be made.^[1][2][3]

Again, women with thyroid conditions should consult with their health care providers before and during the pregnancy for an individualized treatment plan.

During pregnancy, the body needs higher amounts of some nutrients to support the health of both the mother and fetus. In addition to making sure thyroid hormone levels are within the normal range, it is recommended that pregnant women maintain a balanced diet and take prenatal vitamins. Affected women should also speak with their health care provider about their intake of iodine, which is necessary for thyroid health.

The thyroid uses iodine to make thyroid hormone, so iodine is particularly important for a pregnant woman. The fetus only gets iodine from the mother's diet, so women need more iodine during pregnancy. However, people with an autoimmune thyroid disease may be sensitive to harmful side effects from iodine. Taking iodine drops or eating foods containing large amounts of iodine (such as seaweed, dulse, or kelp) may worsen hypothyroidism. Changes in diet and the use of dietary supplements (especially during pregnancy) should always be discussed with a health care provider to make sure any changes or additions to the diet are safe for both the mother and developing fetus.^[2]

We are not aware of recommended alternative treatments for pregnant women with Hashimoto's syndrome. While there is some literature that discusses complementary and alternative therapies for thyroiditis in general, we are not aware of therapies specific to pregnant women. Alternative therapies may help when used along with medications prescribed by your doctor, but it is strongly recommended that affected people first discuss with their doctor any alternative therapies they are considering (especially before or during pregnancy). Some therapies and supplements can interfere with conventional medications or affect other processes in the body.^[4][5]