I have new daughter birth 3 months, expert doctor said irritation inside her mouth and her spo2 shown between 88% - 92% at 40% o2, anybody consult me?

Confusing question: The information you provided is not helpful.There is no particular link between mouth irritation and the need for oxygen. Your 3 mo seems to have a lung/respiratory problem and the more common at that age include pneumonia or bronchiolitis. Both can cause a baby difficulty in breathing and a need for oxygen, care is supportive and includes IV fluids, oxygen and other treatments depending on the c.