Unnatural Selection

A Mutation of Genetics

More and more couples pursuing IVF are also using genetic tests to determine which embryos to transfer into the womb. Most commonly, preimplantation genetic diagnosis (PGD) is done, to identify serious diseases when one or both parents are carriers. Preimplantation genetic screening (PGS) is an exploration, not looking for a particular disease, but to see if any worrisome disease shows up. Recent advances in technology opened the door to even broader screening. Meanwhile, embryos can be frozen pending results of the tests and discussion with the couple.1 Thanks to such technologies, the ethical stakes are being raised, and not necessarily in the direction one might expect.

In late 2011, a group of...