The exact cause is not known but it is believed to be an autoimmune disease very similar to Hashimoto’s thyroiditis. In fact, these two disorders cannot be distinguished from one another on pathology specimens. As in Hashimoto’s thyroiditis, postpartum thyroiditis is associated with the development of anti-thyroid (anti-thyroid peroxidase, antithyroglobulin) antibodies. Women with positive antithyroid antibodies are at a much higher risk of developing postpartum thyroiditis than women who do not have have positive antibodies. It is believed that women who develop postpartum thyroiditis have an underlying asymptomatic autoimmune thyroiditis that flares in the postpartum period when there are fluctuations in immune function.

Generally, you will not be required to be fasting on the day of your appointment. During the thyroid biopsy, ultrasound gel will be applied to the neck to obtain ultrasound images. This gel is water soluble and non-toxic, but may get on clothing or jewelry. You may wish to wear comfortable clothing and take off any jewelry from around the neck for the procedure.