pam_childbirth_piety_reward_effect

pam_childbirth_piety_reward_effect = {
	if = {
		limit = { rite = { rite_has_parameter = piety_from_childbirth_active } }
		if = {
			limit = { scope:child = { has_any_negative_bastard_trait_trigger = no } }
			add_piety = {
				value = major_piety_gain
				if = { limit = { any_child = { is_twin_of = scope:child } } add = major_piety_gain }
				if = { limit = { any_child = { count >= 3 is_twin_of = scope:child } } add = major_piety_gain }
			}
		}
		else = {
			add_piety = {
				value = minor_piety_gain
				if = { limit = { any_child = { is_twin_of = scope:child } } add = minor_piety_gain }
				if = { limit = { any_child = { count >= 3 is_twin_of = scope:child } } add = minor_piety_gain }
			}
		}
	}
	pam_childbirth_spiritual_fulfillment_reward_effect = yes
}

As written in game/common/scripted_effects/pam_effects.txt.