Leaking amniotic fluid (premature rupture of membranes)

Could I be leaking amniotic fluid?

Yes, it's possible that during pregnancy your amniotic sac could break and leak amniotic fluid before you're in labor. If that happens, you have one of these conditions:

PROM stands for premature rupture of membranes, also called prelabor rupture of membranes. It means that your water breaks after 37 weeks of pregnancy (when you're considered full-term). PROM happens in between 8 and 15 percent of pregnancies.

PPROM stands for preterm premature rupture of membranes, or preterm prelabor rupture of membranes. It means that your water breaks before 37 weeks of pregnancy. PPROM, which is more serious because it can lead to premature labor and birth, happens in only about 3 percent of pregnancies.

The amniotic fluid protects and cushions your baby in the womb. It increases during pregnancy until about 36 weeks, when it's about a quart of liquid. Then the amount decreases slightly.

Usually, when your amniotic sack ruptures (your water breaks), it's a sign that labor will soon begin. If labor doesn't start within 6 to 12 hours, the risk of infection increases.

If you have PROM or PPROM, you'll need to stay in the hospital until your baby is born.

Is PROM or PPROM dangerous?

PROM or PPROM can usually be managed without causing serious problems for you or your baby, but possible complications include:

• Compression of the umbilical cord, if it's not surrounded by enough amniotic fluid.
• Infection of the placenta
• Placental abruption
• Postpartum infection

The highest risks of PPROM come from having your baby prematurely. If you have PPROM, you're also at higher risk of your baby being in breech or another abnormal birthing position.

What causes PROM or PPROM?

PROM is usually caused by uterine contractions weakening the membranes. It often happens without any risk factors or obvious cause. Some women are at higher risk of PPROM than others, though. These include those who:

• Had PPROM in a previous pregnancy
• Smoke cigarettes during pregnancy
• Have vaginal bleeding during the second and third trimesters
• Have infections of the uterus, cervix, or vagina, or amniotic fluid
• Are underweight (have a low BMI) with poor nutrition
• Have a short cervical length
• Use illicit drugs

Are there other reasons why my amniotic fluid might be low?

Yes, your fluid may be low for other reasons besides rupturing your membranes. Low amniotic fluid volume is called oligohydramnios. The most common cause of oligohydramnios in the third trimester is PROM/PPROM. But there are other possible causes, including problems with the placenta, having a small baby (small babies produce less amniotic fluid), and being well past your due date.

Oligohydramnios caused by rupture of membranes is usually harmless. But if the lack of amniotic fluid – which normally cushions the umbilical cord – causes the umbilical cord to become compressed, it can prevent your baby from getting enough food and oxygen.

Oligohydramnios with PPROM is also problematic when PPROM occurs very early in pregnancy. Amniotic fluid is needed to help mature the baby’s lungs. The lack of amniotic fluid in this case can also be associated with birth defects, miscarriage or stillbirth.

What does amniotic fluid smell like and look like?

Amniotic fluid is odorless and clear, though sometimes it's tinged with blood or mucus. If amniotic fluid is infected, it may have a foul smell.

If the amniotic fluid is tinged with green or brown, this may be meconium, which means that your baby has had a bowel movement. This can potentially cause breathing problems for your baby at delivery.

How can I tell if I'm leaking amniotic fluid?

You might be able to tell by examining and smelling the liquid, though it can be difficult to tell the difference between amniotic fluid and urine. They have different smells: Urine smells like ammonia, while amniotic fluid typically smells mild and even sweet. Amniotic fluid can look a bit yellow, and very dilute urine can look clear, so you may not be able to distinguish by color.

Here's an amniotic fluid leak test you can do at home:

• Empty your bladder and put on a panty liner or sanitary pad.
• Wear the pad for half an hour or so, then examine any fluid that has leaked onto it.
• If it looks yellow, it's probably urine; if it looks clear, it's probably amniotic fluid. But this can be tricky, so if your pad is soaked, call your caregiver. She can determine whether you're leaking amniotic fluid.

Another way to test is to squeeze your pelvic floor muscles tight. If you stop leaking, it's probably urine that's been leaking. If you still leak, it's probably amniotic fluid.

Should I call the doctor if I think I'm leaking amniotic fluid?

Yes. Tell your provider right away if your water breaks as well as if you think you're leaking amniotic fluid at any time in your pregnancy. Tell her what time the leaking started and what color the fluid is.

To avoid introducing bacteria into the vagina, don't use tampons or douche or have sex before seeing your caregiver.

What will happen if I'm leaking amniotic fluid?

Your caregiver may confirm that you're leaking amniotic fluid by testing it. There are several methods for testing amniotic fluid; they all involve a sterile speculum exam:

• Pooling. Your provider will insert the speculum and look at the cervix. Fluid will come out of your cervix and pool inside the speculum.
• pH test. This tests the acid level of the fluid. Amniotic fluid has a higher pH than normal vaginal fluids.
• Microscope. The amniotic fluid, once dry, will have a fern-leaf pattern under the microscope.
• Dye test. If your caregiver thinks you're leaking amniotic fluid but all the other tests are inconclusive, she may inject blue dye into the amniotic sac and have you wear a sanitary pad. If the dye shows up on the pad, it will mean that you're leaking amniotic fluid. This test only rarely needs to be done.

To look at how much fluid is surrounding your baby, your caregiver may also do an ultrasound.

How your pregnancy is handled will depend on how far along you are, how your baby is doing, and whether you have signs of other complications, such an infection or placental abruption.

If you're at least 37 weeks, your caregiver will probably recommend proceeding toward delivery via induction or cesarean section, depending on your history.

If you're between 34 and 37 weeks, and you're leaking amniotic fluid, your caregiver may recommend induction (to avoid infection), or she may try to delay delivery to give your baby a chance to develop further. You and your baby would be carefully monitored during this time.

If you're between 24 and 34 weeks, your caregiver will try to delay labor and delivery. You may be given:

• Antibiotics to prolong latency (time from rupture of membranes until delivery)
• Steroids to help your baby's lungs mature in case he arrives early
• Magnesium sulfate (prior to 32 weeks) to reduce the risk of neurological impairment in the baby

Your caregiver will monitor you and your baby in the hospital. Once your baby is strong enough, your labor will be induced.

If you're earlier than 23 or 24 weeks and you're leaking amniotic fluid, your caregiver will consult with you about the outlook for your baby and the options for your pregnancy. Your baby would be considered extremely premature if he were to be born at this time, even though babies can survive outside the womb at around 23 weeks' gestation.

Learn more:

• Pregnancy symptoms you should never ignore
• Vaginal odors and discharge during pregnancy
• How will I know I'm in labor?
• When should I call my doctor with a pregnancy concern?
• The ultimate pregnancy to-do list: Third trimester