Preferred Medications:
1. Propylthiouracil (PTU): Recommended before conception, during the first trimester, and postpartum.
2. Carbimazole: Preferred during the second and third trimesters.
Risks:
i. PTU: Carries a risk of maternal hepatotoxicity.
ii. Carbimazole: Associated with foetal aplasia cutis and omphalocele.
General Considerations:
Both medications cross the placenta, so the lowest effective dose should be used.
Radioiodine Therapy: Contraindicated during pregnancy.
Surgical Intervention: Partial thyroidectomy can be performed in the second trimester if hyperthyroidism cannot be controlled with medication.