Dual Cause of Recurrent Pregnancy Loss: Hashimoto's Thyroiditis and Inherited Protein S Deficiency

Abstract Recurrent pregnancy loss (RPL) is a rare occurrence in routine medical practice complicating 1-3% of all pregnancies. They represent a real diagnostic challenge due to the multitude of possible etiologies, and remain unexplained in more than 50% of cases. We report the original observation of a 32-year-old Tunisian woman investigated for six recurrent early miscarriages. The investigations concluded with a dual etiology: Hashimoto's thyroiditis (free thyroxine at 6 pmol/, thyroid stimulating hormone at 12.4 µIU/mL, positive anti-thyroglobulin antibodies at 32.8 IU/ml, and positive anti-thyroperoxidase (anti-TPO) antibodies at 677 IU/ml) with inherited thrombophilia (protein S deficiency of 41%). This association, however rare and unusual, deserves to be recognized by clinicians to avoid diagnostic delays and ensure proper management of recurrent miscarriages.