These companies help parents try to pick their babies' traits. Experts are wary

Justin Schleede is the executive lab director at Herasight, a company that screens embryos for health risks and traits such as height, longevity and IQ. Kate Medley for NPR hide caption toggle caption Kate Medley for NPR Get the latest on the science of healthy living in the NPR Health newsletter , sent weekly. Justin Schleede reaches onto a black lab bench to pick up a tray of small plastic tubes. "These are saliva samples as well as blood," says Schleede, a geneticist who runs Herasight Inc. …