posted on Mar, 30 2010 @ 09:05 AM
Depends on the mythology you go with really. Different vampire mythologies treat it differently.
Even in the Blade mythology, in most cases, the baby would die. Blade was simply the one in a million type example....the fluke survivor hybrid.
If it was more reliable, then the vamps would have had stables of men and women, impregnated the women, they turned them, to create Daywalkers.
Wasn't that simple, as almost all, maybe even all, would die anyhow....so they looked for other ways.