There are many ways to determine if there is amniotic fluid flowing: first, vaginal speculum examination. The vaginal speculum is generally recommended to take a truncated position and use a speculum to peer into the vagina to see if there is a pool of amniotic fluid in the posterior vaginal vault, and also to observe if there is amniotic fluid flowing out of the cervical opening. If you can see the amniotic pool and the amniotic fluid at the cervical os, this is the most intuitive way to diagnose premature rupture of membranes and amniotic fluid flow. Secondly, the pH test paper to detect. If the amniotic fluid is not flowing a lot, you can use pH test paper to detect the fluid in the posterior vault. The vagina is an acidic environment, while amniotic fluid is alkaline. After the water breaks, the amniotic fluid flows into the vagina, the vaginal discharge test will show an alkaline change, and the pH test paper will show a blue change. Premature rupture of membranes is also considered and the pH test has a false positive rate. You can also monitor the change of amniotic fluid through ultrasound dynamically to help determine if it is amniotic fluid.