Premature rupture of membranes, also known as water breaking or membrane rupture, refers to the rupture of the membranes before the onset of labor, causing amniotic fluid to intermittently flow out from the uterine cavity. This can pose certain risks, including umbilical cord prolapse, placental abruption, intrauterine infection, and fetal hypoxia. The diagnostic methods for premature rupture of membranes include the following: First, through clinical symptoms, if a large amount of fluid is found flowing out from the vagina, it can generally be determined as premature rupture of membranes. Second, if the amount of vaginal discharge is relatively small, in this case, pH test strips can be used for detection. When the pH test strips change color, it can be determined as water breaking. Third, ultrasound can be used as an auxiliary diagnostic method, as a decrease in the amount of amniotic fluid due to premature rupture of membranes can be detected through ultrasound.