Definition

Premature rupture of membranes (PROM) at term is the breaking of the amniotic sac more than one hour before labor begins. The sac contains amniotic fluid and the developing baby. With PROM, the amniotic fluid inside the sac leaks or gushes out of the vagina. This is also known as your water breaking.

Fetus in the Amniotic Sac Copyright © Nucleus Medical Media, Inc.

Call your doctor right away if you suspect that your water has broken. Rupture of the membranes is a normal occurrence during labor, and often signals the beginning of labor. When it occurs on its own without contractions starting within an hour, other abnormal causes have to be considered and evaluated.

Causes

PROM is caused by weakening and/or thinning of the opening of the membrane.

Risk Factors

Factors that may increase your chance of PROM:

• PROM in earlier pregnancies
• Infection in the amniotic sac
• Infections of the vagina, uterus, or membranes surrounding the fetus
• Other infections in mother, such as chlamydia
• Early dilation or changes in the cervix
• Bleeding during the pregnancy
• Amniocentesis
• Nutritional deficits
• Low body mass index
• Smoking during pregnancy

Symptoms

The main symptom of PROM is fluid leaking from the vagina. You may experience a sudden gush of fluid or a slow, constant trickle. It can be difficult to distinguish between a slow amniotic trickle or urine. Your doctor can do simple tests to determine this.

Symptoms may include a fever above 100.4°F (38°C). If you have any of these symptoms, call your doctor right away.

Complications from PROM may include:

• Fetal infection
• Uterine infection
• Placenta separates from the uterus before the baby is delivered— placental abruption
• Umbilical cord is squeezed between the baby and the pelvis— prolapsed umbilical cord

Diagnosis

If a large amount of fluid is leaking from the vagina, diagnosing PROM can be straightforward. To confirm the diagnosis, the doctor may do the following tests:

• Visual exam—the doctor may be able to see a trickle of fluid through the cervix, or a pool of fluid collected behind the cervix
• Nitrazine paper test—the doctor puts a small amount of fluid on a piece of paper to see if it is amniotic fluid
• Microscopic exam of the fluid

The doctor will also check you for fever and other signs of infection. Your baby will be monitored for any signs of distress.

Treatment

Labor usually begins within hours after PROM. If labor does not begin soon after your water breaks, the risk of infection increases. In many cases, labor will be induced by giving you medications. Antibiotics may also be given.

You and your baby will be watched closely to look for signs of any problems developing. For example, your baby’s heart rate will be monitored.

Prevention

There are no current guidelines to prevent PROM. Vitamin C may help lower the risk. You can also take steps for a healthier pregnancy, like quitting smoking.