I work in the medical field and am also a stutterer. I have similar fears at times, but I remind myself that people pass on much more life-threatening or debilitating diseases to their children. Things like Huntington's Disease, diabetes, all sorts of genes for cancers, clotting disorders that can lead to strokes, psychiatric disorders like bipolar disorder or schizophrenia, just to name a few. Not to mention, children who are born into households of abuse and neglect. We would all try to pass on perfect genetic material to our children if we could and give them the best childhood we could, but there's only so much we can control. More important than anything else is being a caring, supportive, loving parent. This will give them the resilience to withstand anything life throws at them. Also for what it's worth, my stutter is likely genetic from my mother's side of the family (I have two maternal uncles who stutter), and I have never for a second blamed her or held it against her.