Here's code from my cheat mod that does this, you can add a trigger of any_dynasty_member = { ai = no } then add it to on_birth section in mod/common/on_actions.txt
character_event = {
id = cheat.2
is_triggered_only = yes
hide_window = yes
immediate = {
remove_trait = clubfooted
remove_trait = harelip
remove_trait = hunchback
remove_trait = lisp
remove_trait = stutter
remove_trait = slow
remove_trait = imbecile
remove_trait = inbred
remove_trait = weak
remove_trait = ugly
remove_trait = sickly
remove_trait = stressed
remove_trait = ill
remove_trait = wounded
remove_trait = drunkard
remove_trait = pneumonic
remove_trait = maimed
remove_trait = syphilitic
remove_trait = depressed
remove_trait = lunatic
remove_trait = possessed
remove_trait = has_grey_plague
remove_trait = crippled
remove_trait = has_pox
remove_trait = has_greyscale
remove_trait = has_bubonic_plague
}
option = {
if = {
limit = {
is_ill = no
NOT = { health = 5 }
}
health = 0.5
character_event = { id = cheat.2 }
}
if = {
limit = {
is_ill = no
health = 6.6
}
health = -0.5
character_event = { id = cheat.2 }
}
if = {
limit = {
is_ill = no
NOR = {
trait = dragon
culture = dragon
religion = dragon_rel
culture_group = winter_group
culture_group = old_races
culture_group = unoccupied_group
has_character_modifier = sinfertile
trait = celibate
}
NOT = { fertility = 0.6 }
}
fertility = 0.05
character_event = { id = cheat.2 }
}
}
}