Via explains that if she has children, there's a 50-50 chance that she'll pass the gene on to them, but only a one in four chance that they'll look like August. August is guaranteed to pass the gene onto his children, but if he marries someone who isn't a carrier, their children won't look like him. Via says that over the years, doctors have drawn hundreds of Punnett squares for Mom and Dad to explain August's genetics. She says that she likes how doctors talk, using words that she doesn't understand to explain things she can't understand. Those words explain babies that won't be born, just like Via's.
At the end of this chapter, Via takes the stance that she doesn't feel comfortable having children when there's a possibility that they'd look like August. This probably has to do with the way that Via sees August move through the world with difficulty and be punished for his looks. However, it may also have something to do with the fact that Via has been somewhat of a caregiver for August since his birth, which is a burden she may not want to pass on.