About 300,000 to 400,000 fetuses per year from mothers with diabetes develop neural tube defects — when the tissue that eventually forms the brain and spinal cord fails to form properly — which can lead to miscarriage or profound disability. Now using studies in mice, researchers have identified the mechanism behind these structural birth defects, which they say is due to the neural tissue aging prematurely, halting its growth before it has made enough cells to finish forming the neural tube.