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

Health These companies help parents try to pick their babies' traits. Experts are wary May 6, 20262:30 PM ET Rob Stein 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, opaque plastic tubes. Living Better The oldest millennials are 45! This tool helps plan for longevity "These are saliva samples as well as blood," says Schleede, a geneticist who runs Herasight Inc.'s lab in Morrisville, N.C. "We also get cells from the embryos." Herasight, which is named after Hera, the Greek goddess associated with fertility, is one of a handful of new companies that analyze samples like these for a controversial new type of genetic testing: polygenic embryo screening. Like high-tech fortune-telling, the screening estimates the chances that embryos will produce children at risk for thousands of illnesses, from rare inherited disorders such as Tay-Sachs and cystic fibrosis to common diseases with genetic factors such as cancer, heart disease, diabetes and Alzheimer's. Sponsor Message "For people that are risk averse and don't want to simply roll the dice, they come to us to try to get as much genomic information to pick embryos for the purpose of having happy, healthy, disease-free children," says Schleede. Some companies, like Orchid Health, based in Palo Alto, Calif., only calculate health risks. Herasight goes further by also predicting height, BMI, longevity and even IQ. Nucleus Genomics in New York lets prospective parents try to select even more traits, including eye color, hair color, propensity for baldness and acne, and whether a child will be left-handed. "We call it genetic optimization," says Kian Sadeghi, founder and CEO of Nucleus Genomic...