Premature birth, compared to miscarriage and full-term birth, is defined differently. A miscarriage refers to childbirth before 28 weeks, and a full-term birth is one that occurs after 37 weeks. Births that occur between 28 weeks and 36 weeks plus 6 days are collectively referred to as premature births. During this period, the fetus is relatively larger and has a certain level of maturity, so the survival rate is relatively high. However, it still falls short when compared to full-term infants. Generally, 34 weeks is used as a boundary: infants born from 28 to 34 weeks are referred to as early preterm, while those born between 34 weeks and 36 weeks plus 6 days are considered late preterm. Therefore, premature births are divided into these two main categories. In clinical practice, if there are signs of premature birth, it is recommended to try to extend the gestational age and aim for childbirth during the late preterm period.