Simone Collins knew she was pregnant the moment she answered the phone. She was on her sixth round of in vitro fertilization treatments and had grown used to staffers at Main Line Fertility starting this kind of call with the words “Oh, hi, Simone,” in a subdued tone, voices brimming with sympathy. This time, though, on Valentine’s Day, the woman on the other end belted out a cheery “Oh, hi, Simone!” Embryo 3, the fertilized egg that Collins and her husband, Malcolm, had picked, could soon be their daughter—a little girl with, according to their tests, an unusually good chance of avoiding heart disease, cancer, diabetes, and schizophrenia.
This isn’t a story about Gattaca-style designer babies. No genes were edited in the creation of Collins’s embryo. The promise, from dozens of fertility clinics around the world, is just that the new DNA tests they’re using can assess, in unprecedented detail, whether one embryo is more likely than the next to develop a range of illnesses long thought to be beyond DNA-based predictions. It’s a new twist on the industry-standard testing known as preimplantation genetic testing, which for decades has checked embryos for rare diseases, such as cystic fibrosis, that are caused by a single gene.