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Prelabor Rupture of the Membranes (PROM)


The Manual's Editorial Staff

Reviewed/Revised Sep 2023
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What is prelabor rupture of the membranes (PROM)?

When you're pregnant, your baby grows in amniotic fluid inside your uterus (womb). The fluid and the baby are inside a sac called the amniotic sac. The sac is made of a thin but strong membrane that keeps the fluid from leaking out. When you go into labor, the amniotic sac breaks open (ruptures) and amniotic fluid flows out of your vagina. This is often referred to as your water breaking. If amniotic fluid leaks before you go into labor, you have what's called prelabor rupture of the membranes (PROM).

  • Labor usually starts soon after your water breaks

  • If labor doesn't start within 12 hours after your water breaks, you and your baby are at a higher risk of infection

  • Doctors will usually start your labor with medicine if you're 34 or more weeks pregnant

  • Doctors may try to put off your labor with medicines if you're less than 34 weeks pregnant

Call your doctor or midwife right away if you think your water broke.

How do I know if my water broke?

Clear fluid will flow out of your vagina, either as a gush or a trickle.

After your water breaks, you usually begin to have labor contractions within 12 to 48 hours if you're more than 34 weeks pregnant. If it's earlier in your pregnancy, it can take 4 days or longer for your contractions to start.

What are the risks if my water breaks too early?

If your water breaks too early, germs can get into your uterus and cause infection. You may have:

  • An infection in your uterus

  • An infection in your unborn baby

  • Your baby in an unusual position

Infection in your uterus can cause symptoms such as:

  • Fever

  • Heavy or bad-smelling discharge (fluid) from your vagina

  • Belly pain

Other problems you may have if your water breaks too early include:

Preterm birth gives your baby a higher chance of:

How will my doctor or midwife confirm that my water broke?

The doctor or midwife will examine your vagina and cervix (the lower part of your uterus) to confirm that your water broke. The doctor or midwife will also estimate how much your cervix has opened (dilated).

If there are signs of an infection, the doctor may take a sample of amniotic fluid to test it.

What will the doctor or midwife do if my water broke too early?

If you're 34 or more weeks pregnant, doctors will start your labor with medicine (induce labor).

If you're less than 34 weeks pregnant, doctors will try to prevent labor with medicines and watch for problems. Doctors will usually:

  • Keep you in the hospital

  • Have you rest

  • Check your temperature and heart beat at least 3 times a day

  • Give you antibiotics to prevent infection

  • Give you medicines to help your unborn baby's lungs develop

  • Give you medicine to prevent your unborn baby's brain from bleeding (if less than 32 weeks pregnant)

If your baby is in severe distress or your uterus is infected, your doctor or midwife will induce labor and deliver the baby regardless of how many weeks pregnant you are.

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