Management of Hyperthyroidism in Pregnancy
Diagnosis and Initial Evaluation
- The American Academy of Family Physicians recommends TSH and Free T4 or Free T4 Index (FTI) testing in pregnant women with suspected hyperthyroidism 3
- Biochemical hyperthyroidism associated with hyperemesis gravidarum rarely requires treatment unless other signs of clinical hyperthyroidism are present, according to the American Academy of Family Physicians 3
- Untreated hyperthyroidism during pregnancy increases risks of severe preeclampsia, preterm delivery, heart failure, miscarriage, and low birth weight, as stated by the American Academy of Family Physicians 4
Medication Management
- The American Academy of Family Physicians recommends propylthiouracil (PTU) as the preferred medication during the first trimester 2
- The goal is to maintain Free T4 or FTI in the high-normal range using the lowest possible thioamide dosage, as recommended by the American Academy of Family Physicians 5
- Monitor Free T4 or FTI every 2-4 weeks to adjust medication dosage, according to the American Academy of Family Physicians 5
- TSH levels should be checked every trimester once stable, as stated by the American Academy of Family Physicians 6
Special Considerations
- Thyroid storm is a medical emergency with high risk of maternal heart failure, and treatment includes propylthiouracil or methimazole, potassium/sodium iodide solutions, dexamethasone, and supportive care, according to the American Academy of Family Physicians 3
- Women with Graves' disease should be monitored for normal fetal heart rate and appropriate growth, as recommended by the American Academy of Family Physicians 5
- The newborn's physician should be informed about maternal Graves' disease due to risk of neonatal thyroid dysfunction, according to the American Academy of Family Physicians 5
Alternative Treatments
- Thyroidectomy should be reserved for women who do not respond to thioamide therapy, as stated by the American Academy of Family Physicians 5
- Radioactive iodine (I-131) is absolutely contraindicated during pregnancy, according to the American Academy of Family Physicians 5
- Women should not breastfeed for four months after I-131 treatment, as recommended by the American Academy of Family Physicians 6
Postpartum Considerations
- Women treated with either propylthiouracil or methimazole can safely breastfeed, according to the American Academy of Family Physicians 5
- Monitor for postpartum thyroiditis in women with history of thyroid dysfunction, as recommended by the American Academy of Family Physicians 6