After 29 weeks of pregnancy, if the baby is born prematurely, it is called preterm birth. When preterm labor occurs, there are some early signs, mainly manifesting as the onset of abdominal pain, which is persistent and gradually worsens. Additionally, due to the contraction of the uterus, the abdomen becomes hard and localized muscle tension occurs, leading to a feeling of swelling. Moreover, when the amniotic fluid ruptures, the pregnant mother will feel a flow of liquid from the vagina and there will be an increase in intestinal activity compared to usual, along with some abnormal vaginal discharge. These are some of the signs of preterm labor.