I remember a particularly awkward encounter from my training, where a very pregnant woman arrived at the hospital in wet formal attire. While dancing to “Take a Chance on Me” by ABBA at her sister’s wedding, her water broke right there on the dance floor. Several other members of her family and wedding party had excitedly followed her to the hospital, thinking the family would experience a wedding and birth on the same night. After a thorough exam, I realized that her water was not broken. I then had to delicately explain to the patient and her extended family that she actually had just peed.
While a woman's water breaking always seems obvious on TV, in real life, it can sometimes be difficult to tell whether your water broke, you peed yourself, or you simply lost your mucous plug.
As the baby grows inside the uterus, it floats in the amniotic fluid, which is a clear liquid – the consistency of water. Think of the baby growing in a giant water balloon, where the “water” is amniotic fluid and the “membranes” are the balloon. Many women picture labor starting with a cascading gush of amniotic fluid, but only in 8% of labors will the water break before contractions start. And when water does break, it’s not always dramatic: Sometimes the water balloon doesn’t burst completely and a “slow leak” happens. Picture poking a hole in a balloon with a pin and water continuously trickling out until is empty. No river of fluid, just a confusing trickle than can be hard to distinguish from vaginal discharge or urine.
You would think it would be fairly obvious if a water balloon broke in your pants, but there’s a lot going on in that region during the final months of pregnancy that can make the situation confusing. Your bladder is attached to the front part of your uterus, so as the uterus grows, the position of the bladder gets distorted. The baby’s head also pushes on the bladder as it begins to drop in the birth canal. Additionally, the pelvic muscles that help you control your urine are often weakened during pregnancy; so most women have more trouble controlling their urine in the second and third trimesters. This combination leads to a lot of urinary incontinence during pregnancy especially in the final weeks of pregnancy when baby’s noggin starts headbutting the bladder.
Many pregnant women have significantly more vaginal discharge toward the end of pregnancy, often so much that they need to wear a pad, and this discharge can create enough moisture to be confused with amniotic fluid. In the last weeks of pregnancy, as the cervix starts to dilate, it will begin to secrete mucous as well. Sometimes this comes out in a large chunk that is often referred to as a mucous plug, other times it will come out as small amounts in regular intervals. Vaginal discharge and mucous are typically white or yellow, and while they can be heavy at times, they are usually not clear and continuously leaking like amniotic fluid.
When my patients call to tell me they have a small amount of leaking and are unsure if their water has broken, I tell them to fully empty their bladder and thoroughly dry off their external genitals. After everything is dry, I have them sit on a fresh towel for a half hour. If their water has broken, the fluid will usually continue come out getting the new towel at least a little wet. If the towel is completely dry for 30 minutes, then it’s more likely that the leaking was urine or discharge. If you want to get a little more scientific at home, you can try to test the mystery fluid with pH paper (amniotic fluid will turn it blue, while vaginal discharge will turn it yellow). But this can be tricky because urine and amniotic fluid have a similar pH. There is also an over-the-counter test in the form of a special panty liner that has been shown to diagnose ruptured membranes accurately about 95% of the time.
If you have any doubts if your water could be broken, you should contact your provider and be evaluated. The longer your water is broken, the higher the chance that bacteria could enter the uterus and possibly causing infection in the baby, especially if the membranes have been ruptured for several days. Your provider will often perform a test where they gather fluid from the vagina using a speculum. The test involves looking at your cervix to see if any fluid is coming out and if it’s thick like mucous or more like water/amniotic fluid. Then they test the fluid’s pH and look at the fluid on a slide under the microscope. Amniotic fluid has a high salt content (I got splashed in the face once and accidently discovered that it tastes like coconut water. I can no longer drink coconut water), and when it dries the fluid looks like the branches of a fern. Alternately, you doctor can perform a test in which a swab is placed in the vagina then sent to the hospital lab for testing, usually getting back results within an hour. Both of these options are about 95% accurate. The level of amniotic fluid can also be checked by ultrasound, but if it’s a small, early leak, the fluid will sometimes still look normal.
What happens if you are in the 5% where the test is wrong? Most of the time once the water is broken, labor will start within 24 hours, but occasionally it will not, and this can put the baby and mom at increased risk of infection. If you have a continuous watery discharge, then follow back up with your provider. If it’s a tiny leak, sometimes the tests are inaccurate initially.
When your water breaks, most of the time it is an obvious river of amniotic fluid that continues to flow. If you aren’t quite sure if it might be urine or discharge causing the incident, then try my towel trick; but if there is any doubt, follow up with your provider for a more official test.