I’d never considered this side of having children later in life. From Julie Shulevitz’s essay excerpted in the link above:
What haunts me about my children, though, is […] the actuarial risk I run of dying before they’re ready to face the world.
Older parents die earlier in their children’s lives. […] A mother who is 35 when her child is born is more likely than not to have died by the time that child is 46. The one who is 45 may have bowed out of her child’s life when he’s 37. The odds are slightly worse for fathers: The 35-year-old new father can hope to live to see his child turn 42. The 45-year-old one has until the child is 33.