Past studies have linked prenatal health problems, such as maternal infections or high stress, to an increased risk of mental health disorders later in life, including anxiety. This allowed them to study the impact of prenatal adversity on offspring brain development under controlled conditions. Essentially, prenatal stress appeared to “program” these neurons to overreact, making the offspring more prone to anxiety even in safe environments. They suggest that prenatal stress and maternal infections could program the brain in ways that increase the likelihood of anxiety disorders in adulthood. The study from Weill Cornell Medicine shows that prenatal stress or infection can leave lasting imprints on the brain.