Premature Rupture of Membranes

Premature rupture of membranes occurs when the fluid-filled sac protecting a baby breaks before labor begins, creating risks for both mother and child that require immediate medical attention and careful management decisions.

Table of contents

• What is Premature Rupture of Membranes?
• How Common Is This Condition?
• Signs and Symptoms
• Causes and Risk Factors
• Complications and Risks
• Diagnosis
• Treatment and Management
• Prevention

What is Premature Rupture of Membranes?

Premature rupture of membranes, or PROM, is when your water breaks before labor starts. Healthcare providers may also call it “prelabor rupture of membranes.”^[1] Normally, your membranes rupture after labor or contractions begin.^[1]

During pregnancy, the baby develops inside a fluid-filled sac called the amniotic sac. This sac, which contains amniotic fluid, surrounds and protects the baby throughout pregnancy.^[1] The amniotic fluid plays several important roles: it protects the baby from infection, cushions its movements, and helps develop muscles and bones.^[1] The membranes are sometimes called the “bag of waters,” which is where the term “water breaking” comes from.^[1]

When the membranes break, the amniotic fluid surrounding the baby starts to leak or gush out through the vagina. This can be a problem because without amniotic fluid, the chances of infection, premature birth, and other complications increase.^[1]

If the membranes rupture before 37 weeks of pregnancy, the condition is called preterm premature rupture of membranes (PPROM).^[1] If your pregnancy is fewer than 37 weeks and your membranes rupture, your healthcare provider will decide if delivery is necessary or if labor can be safely delayed. Allowing a pregnancy to continue after the membranes rupture increases the chances of infection and other complications, but premature birth also comes with risks. Your provider will carefully weigh these risks before making a decision.^[1]

How Common Is This Condition?

PROM occurs in up to 10% of all pregnancies.^[1] When PROM happens at term (37 weeks or later), up to 95% of all births occur within 28 hours.^[1] Most women will go into labor on their own within 24 hours after their water breaks.^[5]

PPROM occurs in about 3% of pregnancies.^[1] Studies show that PPROM is more likely to affect twin pregnancies.^[1] PPROM complicates approximately 3% of pregnancies and leads to one third of preterm births.^[7] It is a complicating factor in as many as one third of premature births.^[3]

Signs and Symptoms

The main sign to watch for is fluid leaking from the vagina. It may leak slowly, or it may gush out. You will feel a trickle or gush of uncontrollable fluid from your vagina.^[6] Most women will experience a painless leakage of fluid.^[9] Some of the fluid is lost when the membranes break, and the membranes may continue to leak.^[5]

It can be hard to differentiate amniotic fluid from urine and vaginal discharge. Sometimes when fluid leaks out slowly, women mistake it for urine.^[5] Amniotic fluid usually has no color and does not smell like urine—it has a much sweeter smell.^[5] One helpful method is to place a white paper towel on the fluid. If the fluid is clear and odorless, seek immediate medical attention.^[6]

If you notice fluid leaking, use a pad to absorb some of it. Look at it and smell it to help determine what it might be.^[5] Contact your healthcare provider right away if you believe your membranes have ruptured. You will need to be checked as soon as possible.^[1]

Causes and Risk Factors

PPROM and PROM can have different causes. If your membranes rupture at term (37 weeks of pregnancy), it’s usually from your amniotic membranes weakening from the pressure of contractions.^[1] It’s important to note that just because you can’t feel contractions, your body is still preparing for labor. This means your uterus may be contracting, and your cervix may be thinning and opening without you feeling anything. This can cause the amniotic sac to weaken and eventually rupture.^[1]

Preterm PROM typically occurs due to a medical condition or pregnancy complication, but it can result from unknown causes.^[1] In most cases of PPROM, the cause is not known.^[8] Rupture of the membranes near the end of pregnancy may be caused by a natural weakening of the membranes or from the force of contractions. Before term, PPROM is often due to an infection in the uterus.^[3]

Several risk factors may increase the likelihood of PROM:^[3][5][7]

• Infections of the uterus, cervix, or vagina, including sexually transmitted infections such as chlamydia and gonorrhea
• Previous preterm birth or history of PROM
• Vaginal bleeding during pregnancy
• Cigarette smoking during pregnancy
• Low socioeconomic conditions (as women in lower socioeconomic conditions are less likely to receive proper prenatal care)
• Having a preterm birth in a previous pregnancy
• Having had surgery or biopsies of the cervix
• Too much stretching of the amniotic sac (this may happen if there is too much fluid, or more than one baby putting pressure on the membranes)
• Low body weight
• Procedures such as amniocentesis (a procedure to take a sample of amniotic fluid)

Complications and Risks

When membranes rupture too soon, both the mother and baby face several risks. One of the most common complications of preterm PROM is early delivery. The latent period, which is the time from membrane rupture until delivery, generally is inversely proportional to the gestational age at which PROM occurs.^[7] At term, 95% of patients delivered within approximately one day of PROM.^[7]

If your membranes rupture too soon, the baby is at risk for premature birth or infection. If your baby is born before 37 weeks, they’re at higher risk for complications of being born early. These complications include respiratory issues and trouble staying warm.^[1] Without the protection of amniotic fluid and the amniotic sac, the baby and your uterus are at risk for infection. Infections can become quite serious.^[1]

For the baby, complications may include:^[7][3]

• Respiratory distress syndrome due to underdeveloped lungs
• Difficulty maintaining body temperature
• Cord compression (pressure on the umbilical cord)
• Infection
• Changes in the baby’s position, which can affect delivery
• Necrotizing enterocolitis (a serious intestinal condition)
• Neurologic impairment
• Intraventricular hemorrhage (bleeding in the brain)
• In rare cases, fetal death

For the mother, complications may include:^[2][3]

• Chorioamnionitis (a serious infection of the placental tissues), which can be very dangerous for both mother and baby
• Placental abruption (separation of the placenta from the uterus)
• Problems with the umbilical cord
• Need for surgical or cesarean section (C-section) delivery

Diagnosis

Diagnosis is suspected based on symptoms and examination and may be supported by testing the vaginal fluid or by ultrasound.^[9] At the hospital, simple tests can confirm that your membranes have ruptured.^[5]

Your healthcare provider will ask you questions about your pregnancy and your symptoms. Then your healthcare provider will give you an exam. The exam may be done with a tool called a speculum to look inside your vagina.^[8] Speculum examination to determine cervical dilation is preferred because digital examination is associated with a decreased latent period and with the potential for adverse consequences.^[7]

During the speculum vaginal examination, your healthcare provider will look for:^[4]

• Pooling of fluid in the vagina or leakage of fluid from the cervix
• Ferning of the dried fluid under microscopic examination (when amniotic fluid dries, it has a fern-like pattern)
• Alkalinity of the fluid as determined by nitrazine (phenaphthazine) paper

Pooling of fluid is by far the most accurate for diagnosis of rupture of membranes.^[4] Blood contamination of the nitrazine paper and ferning of cervical mucus may produce false-positive results.^[4]

Your provider may also remove some fluid to test it. This is to check if it’s amniotic fluid, vaginal fluid, or urine. Testing may include pH (acid-base) balance testing, as the pH balance of amniotic fluid is different from vaginal fluid and urine.^[8]

You may also have an ultrasound exam. This is done to check the amount of amniotic fluid around your baby.^[8] If all fluid has leaked out as in early PROM, an ultrasonographic examination may show absence of or very low amounts of amniotic fluid in the uterine cavity.^[4]

Evidence suggests that the use of biochemical markers to diagnose rupture of membranes in uncertain cases may be appropriate and cost-effective.^[4]

Treatment and Management

Treatment is based on how far along a woman is in pregnancy and whether complications are present.^[9] If your provider finds that you have PROM, you will need to be in the hospital until your baby is born.^[5] Management of PPROM depends largely on gestational age, with delivery often recommended after 37 weeks and more conservative approaches taken for PPROM to balance fetal development with the risk of infection.^[2]

After 37 Weeks (At Term)

If your pregnancy is past 37 weeks, your baby is ready to be born. You will need to go into labor soon. The longer it takes for labor to start, the greater your chance of getting an infection.^[5] In those at or near term without any complications, induction of labor is generally recommended.^[9] You can either wait for a short while until you go into labor on your own, or you can be induced (get medicine to start labor). Women who deliver within 24 hours after their water breaks are less likely to get an infection. So, if labor is not starting on its own, it can be safer to be induced.^[5]

Labor should be induced immediately, generally with oxytocin infusion, to reduce the risk of chorioamnionitis.^[15]

Between 34 and 37 Weeks

If you are between 34 and 37 weeks when your water breaks, your provider will likely suggest that you be induced. It is safer for the baby to be born a few weeks early than it is for you to risk an infection.^[5] Delivery is generally indicated when rupture of membranes occurs at or after 34 weeks’ gestation.^[7]

Between 24 and 34 Weeks

If your water breaks before 34 weeks, it is more serious. If there are no signs of infection, your provider may try to hold off your labor by putting you on bed rest.^[5] In those 24 to 34 weeks of gestation without complications, corticosteroids and close observation is recommended.^[9]

You and your baby will be watched very closely in the hospital. Your healthcare provider will monitor:^[8]

• Signs of labor or contractions
• Your baby’s movement, heart rate, and other tests
• Symptoms of infection (these can include a fever and pain; your baby’s heart rate may also increase)

You may need several medicines:^[8][7]

• Corticosteroids: These medicines can help your baby’s lungs grow and mature. If your baby is born early, their lungs may not be able to work on their own. Corticosteroids can reduce many neonatal complications, particularly intraventricular hemorrhage and respiratory distress syndrome. A single course of antenatal corticosteroids should be given to women with PROM at 24 to 31 weeks’ gestation.^[15]
• Antibiotics: You may need these to prevent or treat an infection. Antibiotics are effective for increasing the latency period. To prolong pregnancy and to reduce infectious and gestational age-dependent neonatal morbidity, a 48-hour course of intravenous ampicillin and erythromycin, followed by five days of amoxicillin and erythromycin, is recommended for expectant management of preterm PROM.^[15]
• Tocolytic medicines: These are used to stop preterm labor. However, long-term tocolysis is not indicated for patients with preterm PROM, although short-term tocolysis may be considered to facilitate maternal transport and the administration of corticosteroids and antibiotics.^[7]

Your provider may do tests to check your baby’s lungs. When the lungs have grown enough, your provider will induce labor.^[5] Your labor likely won’t be induced until at least week 34 of pregnancy, but this may need to be done earlier if there are problems.^[8]

When Infection Is Present

Labor should be induced immediately, regardless of gestational age, in patients with intrauterine infection, placental abruption, or evidence of fetal compromise.^[15] All women with PROM and a viable fetus, including those who are known carriers of group B streptococcus (GBS) or who deliver before their GBS status can be determined, should receive intrapartum chemoprophylaxis to prevent vertical transmission of GBS.^[15]

Prevention

The cause of PPROM is often unknown. There is no way to stop this from happening in most pregnancies.^[8] Most women whose water breaks before labor do not have a risk factor.^[5]

You should take good care of yourself during pregnancy. This means that you should see your healthcare provider as soon as you know you’re pregnant. Keep up with your prenatal checkups.^[8] If you smoke, ask your healthcare provider how to quit.^[8] Do not use tobacco or tobacco-like products, including cannabis, and other substances, as they can harm your health and affect your baby’s growth, health, and the development of their brain and lungs.^[17]

Do not drink alcohol. Alcohol affects everyone differently and may be a risk to your health. Alcohol passes through the placenta to your baby and can cause problems with their growth, health, and development.^[17]