The Ultrasound That Changed Everything

When Dr. Sarah Chen performs a 3D ultrasound at her clinic in Rochester, Minnesota, she often watches the parents' faces more than the screen. "There's this moment," she says, "when they see the fingers. Ten tiny fingers, each one with a fingernail smaller than a sesame seed, and the room goes completely still." She recalls one father, Marcus, a structural engineer who designs bridges for a living, whispering through tears: "I build things for a living, and I couldn't build anything this perfect."…