Where should we draw the line on 'designer' babies?

Where should we draw the line on 'designer' babies?: "Design has permeated pregnancy, babies and all that that entails. And if it floats your boat, why not? We live in a time and in a nation that values – indeed enshrines – free choice. But what if baby design starts earlier? What if we chose to manipulate the genetic make up of our children before they were born?"