Premature birth, as the name implies, occurs when labor happens too early. Premature birth is generally defined by gestational age, specifically when delivery occurs between 28 and 36 weeks and 6 days of pregnancy. In contrast, miscarriage refers to delivery before 28 weeks; full-term birth refers to delivery between 37 and 41 weeks and 6 days; and post-term birth refers to delivery after 42 weeks of pregnancy. Premature birth can be quite harmful to the fetus, as during this period the fetus is smaller in size and less mature. If premature birth occurs, the survival rate of the fetus is relatively low. Causes of premature birth in clinical practice include vaginal inflammation, premature rupture of membranes, twin pregnancy, and shortened cervical canal. Therefore, prevention of premature birth should target these underlying causes.