New research highlights the importance of the thymus in successful pregnancies

How the immune system adapts to pregnancies has puzzled scientists for decades. Now, findings from an international group of researchers, led by experts at Karolinska Institutet in Sweden, reveal important changes that occur in the thymus to prevent miscarriages and gestational diabetes. The thymus is a central organ of the immune system where specialised immune cells called T lymphocytes mature. These cells, commonly referred to as T cells, then migrate into the blood stream and tissues to help combat pathogens and cancer. An important T cell subset, known as a regulatory T cell or Treg, is also produced in the thymus. The main function of a Treg is to help regulate other immune cells. Researchers found that during pregnancy, the female sex hormones instruct the thymus to produce Tregs specialised in dealing with physiological changes during pregnancy.