First examination (first row of images)

Clinical presentation: A 30-year-old woman was referred for evaluation of a newly discovered hypothyroidism.

Palpation: no abnormality.

Result of blood tests: TSH 8.01 mIU/L, aTP0 794 U/mL.

Ultrasonography. The thyroid was hypoechogenic and inhomogeneous and presented fibrotic changes. There were two relatively large hypoechogenic areas in the lower pole of both lobes.

Suggestion: daily 50 microgram levothyroxine.

Second examination 17 months later (second row of images)

Clinical presentation: The patient was referred for follow-up evaluation. The dose of the replacement therapy was elevated to 75 microgram 6 months ago.

Palpation: no abnormality.

Result of blood tests: TSH 1.98 mIU/L.

Ultrasonography. The thyroid became a bit more hypoechogenic. The echogenicity index was above 90% in both lobes. The extent of the echonormal areas has decreased compared with the former examination.

Suggestion: to continue with daily 75 microgram levothyroxine.

Third to fifth examinations during pregnancyat 5th, 15th and 32nd gestational week, respectively (third to fifth rows of images)

Clinical presentation: The patient had no complaints during her pregnancy.

Result of blood tests and suggestions. At the 5th gestational week the TSH was 2.71 mIU/L when we increased the dose to 100 microgram. At the 15th gestational week the TSH was 2.96 mIU/L when we increased the dose to daily 112.5 microgram. At the 32nd gestational week the THS was 1.27 mIU/L. At this time we did not change the dose but suggested to decrease the dose of levothyroxine after delivery to daily 75 microgram.

Ultrasonography. The echogenicity index has decreased dramatically at the first visit during pregnancy and decreased further on the subsequent two examinations.

Comment. This is a rare but impressive example of the influence of preganancy on the activity of autoimmune thyroiditis and therefore on the ultrasound pattern. We did not meet the patient until now after her delivery but it is reasonable to assume that the thyroid became more hypoechogenic after pregnancy. We will extend the case study when the patient visits us again.