IVF clinics have long tested embryos for genetic disorders and abnormalities — but in recent years, new startups have been pushing the envelope of genetic testing, helping parents screen their future children for all kinds of health risks, ranging from diabetes to breast cancer.

Many people see this technology as promising — it can give parents, many of whom have already faced devastating losses, their best shot at having happy, healthy children. But others see a dark side to the advancing field of embryo screening. What happens when testing goes beyond health and parents get the chance to select for other traits, like eye color, height, or intelligence? What does it mean to want “the best” for your child?

On this episode, we look at new and emerging DNA technologies aimed at selecting embryos. We discuss critics’ fears, concerns, and the ethics of embryo screening. We also hear about one experiment from the past that went very wrong.

Also heard on this week’s episode:

• We talk with Nita Farahany — a professor of law and philosophy at Duke University who studies ethical, legal, and social implications of emerging technologies — about the thorny legal and ethical issues surrounding embryo screening.
• Back in the 1980s, a wealthy inventor named Robert K. Graham came up with an idea to make the world a better place — a sperm bank for geniuses. His goal was to create a new generation of intellectual elites, spawned from the sperm of noted scientists. More than 200 children were born from this bank. The new podcast series BioHacked: Family Secrets, hosted by T.J. Raphael, sheds light on this experiment, and introduces us to one of the people who was conceived from one of the donors. We’ll hear an excerpt of his story.