Thyroid Cancer During Pregnancy and Lactation

Abstract The discovery of a thyroid nodule in pregnancy is common, and it must be risk-assessed for thyroid cancer using clinical assessment, specialist neck ultrasound, and sometimes fine-needle biopsy, although scintigraphy is contraindicated. Hormonal changes during pregnancy are associated with thyroid nodule development and growth, but they have not been shown to affect the survival of women diagnosed with thyroid cancer during pregnancy. However, thyroid cancers diagnosed during pregnancy may have a higher risk of persistent or recurrent disease. Aggressive tumors may be resected in the second trimester, although thyroidectomy can often be deferred to the postpartum period. Survivors of thyroid cancer are increasingly presenting for obstetric management, which best occurs in a multidisciplinary setting and with the benefit of preconception assessment of disease status, avoidance of radioiodine for at least 6 months prior to conception, and a prospective plan for levothyroxine replacement.