The Prognosis: The Nobel That Explains How Pregnancy Works

Mary Brunkow’s discovery of the FOXP3 gene reveals why a mother’s immune system can accept her baby without rejection—and why understanding immune tolerance could reshape obstetrics.

In October 2025, the Nobel Prize in Physiology or Medicine was awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for discovering how the immune system learns tolerance—the ability to live in peace with what it might otherwise attack. At first glance, this seems far from obstetrics. But their work helps explain one of pregnancy’s oldest mys…