Clinical presentation: A 38-year-old woman was referred for evaluation of hypothyroidism. The patient has delivered for 10 months.

Palpation. No abnormality.

Laboratory test: TSH 9.02 mIU/L, aTPO 18 U/mL.

Ultrasonography. The thyroid was minimally hypoechogenic and presented a few more hypoechogenic areas.

Diagnosis: Post partum thyroiditis.

Suggestion: TSH determination in 3 months.

Follow-up examinations Three months later the TSH decreased to 5.17 mIU/L while another 6 months later the TSH spontaneously returned to normal level (2.70 mIU/L).