PROM stands for premature rupture of membranes, which means your water breaks before labor contractions begin. It happens in about 8 to 10 percent of all pregnancies. When your water breaks at or after 37 weeks but labor hasn’t started yet, that’s called PROM. When it happens before 37 weeks, it’s called PPROM (preterm premature rupture of membranes), a more serious situation because the baby may not be ready for delivery.
How PROM Differs From Normal Water Breaking
In a typical labor, contractions start first and your water breaks sometime during active labor, often well into the process. With PROM, the order is reversed: the amniotic sac ruptures first, and contractions either follow on their own or need to be induced. If you’re past 37 weeks, this is mostly a matter of timing. Your baby is considered full-term, and your care team will plan delivery relatively quickly to reduce the risk of infection now that the protective barrier around the baby is gone.
PPROM, the preterm version, is a different situation entirely. It accounts for one-quarter to one-third of all preterm births. The earlier it happens, the more complex the decisions become, because every additional day the baby stays in the womb can make a meaningful difference in development.
What It Feels Like
The classic image of water breaking is a dramatic gush, but PROM can also present as a slow, steady trickle that’s easy to confuse with urine or vaginal discharge. Amniotic fluid is typically clear, sometimes with white flecks or tinged with mucus or blood, and it has no odor. Urine, by contrast, usually has a noticeable smell and a yellow color. Normal vaginal discharge tends to be white or yellowish and thicker in consistency.
If you’re not sure what you’re dealing with, empty your bladder first, then place a clean pad in your underwear and check it after 30 minutes to an hour. You can also try tightening your pelvic floor muscles as if stopping your urine stream. If the leaking stops when you do this, it’s likely urine. If the pad is still getting wet, it could be amniotic fluid. Green-tinged or brownish-yellow fluid is a reason to contact your provider immediately, as it may indicate the baby has had a bowel movement in the womb.
How It’s Diagnosed
At the hospital, your provider will typically do a speculum exam to look for fluid pooling in the vagina. Two common bedside tests help confirm the diagnosis. A nitrazine test checks the pH of the fluid: amniotic fluid is more alkaline than normal vaginal secretions, which turns the test paper blue. A ferning test involves drying a sample of the fluid on a glass slide and looking under a microscope for a fern-like crystallization pattern characteristic of amniotic fluid.
These tests are reliable but not perfect. Blood, semen, infection, and even soap can cause false positives on the nitrazine test. Newer biochemical tests exist that are highly accurate (sensitivity above 95%), though the FDA has cautioned providers not to rely on any single test alone. An ultrasound measuring amniotic fluid levels may also be used if there’s still uncertainty after the initial exam.
Risk Factors
PROM can happen without any identifiable cause, but several factors increase the likelihood. Vaginal or urinary tract infections weaken the membranes and are among the most common contributors. A history of PROM or PPROM in a previous pregnancy significantly raises the risk of it happening again. Smoking during pregnancy, carrying multiples, having had certain cervical procedures, and having too much amniotic fluid (polyhydramnios) are also associated with higher rates of membrane rupture before labor.
Risks to Mother and Baby
Once the amniotic sac is broken, the sterile environment protecting the baby is compromised. The primary concern at any gestational age is infection. Chorioamnionitis, an infection of the membranes and amniotic fluid, can develop in the mother and potentially lead to sepsis in the newborn. The risk of infection increases the longer the interval between membrane rupture and delivery.
Other risks include placental abruption, where the placenta separates from the uterine wall, and abnormal fetal positioning since the cushion of fluid that helps the baby move freely is reduced. In the newborn, there’s an elevated risk of bleeding in the brain, which can sometimes lead to long-term developmental issues.
When PPROM occurs very early, before 24 weeks, the risks are more severe. Prolonged loss of amniotic fluid at this stage can affect lung development and cause limb deformities because the baby doesn’t have enough fluid-filled space to move and grow normally.
What Happens After PROM at 37 Weeks or Later
If your water breaks at or after 37 weeks and labor doesn’t start on its own within a reasonable window, your provider will typically induce labor or proceed with delivery. The baby is full-term at this point, so the main goal is getting the baby out before infection has a chance to develop. Most people in this situation deliver without major complications, and the outcome for the baby is the same as any other full-term birth.
What Happens After PPROM (Before 37 Weeks)
Management of PPROM depends heavily on how far along you are.
Before 34 Weeks
The risks of prematurity are high enough that the medical team will usually try to keep the baby in the womb as long as safely possible. This typically means a hospital stay with close monitoring for signs of infection, contractions, and fetal well-being. You’ll receive steroid injections to speed up the baby’s lung development, which significantly reduces the risk of breathing problems after birth. Antibiotics are given to help prevent infection and can also help prolong the pregnancy. If delivery is expected before 30 weeks, a magnesium infusion may be offered to help protect the baby’s brain.
Between 34 and 37 Weeks
This is a gray zone where your care team weighs the risks of prematurity against the risks of infection from continuing the pregnancy. Babies born after 34 weeks generally do well, though they may need some time in the NICU. The decision about when to deliver depends on your specific situation, including how far along you are, whether there are signs of infection, and how the baby is doing on monitoring.
Outcomes by Gestational Age
For PPROM that leads to very early delivery, gestational age is the single biggest factor in how the baby will do. At 25 weeks, survival rates range from 67 to 76 percent. At 24 weeks, survival drops to 42 to 59 percent. At 23 weeks, it’s 23 to 27 percent. Before 23 weeks, survival is rare, around 5 to 6 percent.
Among survivors of very early delivery, developmental outcomes also improve with each additional week. About 17 percent of babies born at 25 weeks have moderate to severe developmental challenges by age 30 months, compared to 30 percent at 24 weeks and 45 percent at 22 to 23 weeks. These numbers underline why, when PPROM happens early, the medical team works so hard to buy extra time in the womb. Even a few additional days can shift the odds.