AIDS can be harmful to a family, transmitted from one parent to the other; if the mother gets it, then becomes pregnant, then the foetus/fetus could have it, too. Also, human papplioma(sp) virus can cause uterine cancer, which in turn may mean a loss of cervix due to surgery, which may mean weeks in bed, again, if she became pregnant, in order for the foetus/fetus to not "fall out."

Then, there's herpes...exposing his wife to any STDs is inexcusable, and could have a peripheral effect on their children, if not direct.