All this creates unprecedented ethical challenges in the immediate future. Consider the parents who use IVF to raise their children’s IQ. If the children repeat the process for another generation, taking advantage of scientific advances during the interim, they could bring the total average gain in the grandchildren north of 10 points—a huge gain. That advantage could be big enough to give the grandchildren radically disproportionate representation at the highest levels of science, finance, information technology, medicine, law and business.

Imagine the behavior of any couple who plan to have a few children and can easily afford the cost of IVF—roughly $11,000 to $12,000. Virtually all upper-middle-class American couples will have it within their power to give their child a wide variety of advantages. How many parents would nonetheless choose to bring a child into the world the old-fashioned way—especially in a world where the increased use of IVF has led to improvements that increase its convenience and lower its costs? IVF could become the norm for the upper middle class. Congress could pass legislation that subsidizes IVF among lower-income populations, but only a highly intrusive policy is likely to stop the magnification of inequality.

Many think genetic enhancement will be a wonderful thing. In some ways, it might be. But if the old-fashioned way of making babies becomes a thing of the past, we may come to miss it for more than sentimental reasons.