Premature rupture of membranes, as the name implies, refers to the rupture of membranes before labor, leading to intermittent leakage of amniotic fluid from the uterine cavity. It is a common cause of miscarriage, premature birth, and fetal hypoxia in the womb. Premature rupture of membranes can occur at any time during pregnancy, generally after 12 weeks of pregnancy when the fetus is already formed and there is a clear presence of amniotic fluid in the amniotic cavity. Therefore, it can occur from after 12 weeks of pregnancy until before childbirth. However, most cases of premature rupture of membranes occur in the late stages of pregnancy, generally after 30 weeks of pregnancy. At this time, the uterus is relatively large and the fetal weight has increased, which increases the stimulation to the amniotic cavity and makes it easily susceptible to external pressure, causing premature rupture of membranes.