pregnancy_termination_attempt_effect

pregnancy_termination_attempt_effect = {
	random_list = {
		100 = { #Pregnancy ends, no negative consequence
			#custom_tooltip = pregnancy_treatment_succeeds_tt
			show_as_tooltip = {
				end_pregnancy = yes
			}
			hidden_effect = {
				trigger_event = {
					id = pregnancy.2003
					days = { 3 10 }
				}
			}
		}
		30 = { #Pregnancy ends, mother becomes Ill
			trigger = {
				NOT = { has_trait = ill }
			}
			show_as_tooltip = {
				end_pregnancy = yes
				add_trait = ill
			}
			#custom_tooltip = pregnancy_treatment_succeeds_tt
			#custom_tooltip = pregnancy_treatment_fall_ill_tt
			hidden_effect = {
				trigger_event = {
					id = pregnancy.2004
					days = { 3 10 }
				}
			}
		}
		100 = { #The pregnancy continues
			custom_tooltip = pregnancy_treatment_fails_tt	
			hidden_effect = {
				trigger_event = {
					id = pregnancy.2005
					days = { 3 10 }
				}
			}
		}
		10 = { #The mother dies
			show_as_tooltip = {
				death = {
					death_reason = death_attempted_treatment
				}
			}
			hidden_effect = {
				trigger_event = {
					id = pregnancy.2007
					days = { 3 10 }
				}
			}
		}
	}
}

As written in game/common/scripted_effects/00_pregnancy_effects.txt.