The sudden release of amniotic fluid is otherwise known as the classic sign of preeminent labour --- the breaking of your water. The problem is, it is not always the dramatic gush of fluid that is portrayed in film and television. When your amniotic sac ruptures before full term (37 weeks), it can actually be an urgent matter, so knowing the difference between amniotic fluid and urine is important.
Only one out of 10 labours begin with an amniotic fluid leak, and an even lower percentage manifests itself as an obvious burst of liquid. Often, when the membranes rupture, it comes out as a slow trickle. Because the uterus sits directly on top of your bladder, your baby's weight and the force of her kicks can cause you to unintentionally dispel small amounts of urine, making you think your water has broken.
The Sniff and Visual Test
The easiest way to tell the difference between amniotic fluid and urine is to take a quick sniff of your wet underwear. Amniotic fluid might have a slightly sweet scent, although most often it is odourless and has no colour. Urine has a stronger smell, although the amount of water you drink can make it less obvious. Urine ordinarily has a yellowish tint to it, although if you are hydrated sufficiently it may be clear as well.
The pH or Nitrazine Test
If you cannot determine if it is your amniotic fluid leaking, get checked out by a health-care provider. He can do a quick in-office test using pH strips or a Nitrazine test, both which turn a specific colour when exposed to amniotic fluid. Both types of tests are quick and painless and can reveal within a few minutes the answer, and then your provider can decide what your next step will be.
Warnings and Tips
If you believe you are leaking amniotic fluid, don't use tampons, have intercourse or take a tub bath while waiting to be evaluated. If you are preterm, contact your doctor right away. If you are at least 37 weeks, you don't need to rush to the hospital, but go ahead and finalise your preparations. Most doctors prefer to not let more than 24 hours pass from amniotic sac rupture to delivery because of your risk of infection.