Leaking amniotic fluid, also called rupture of membranes (ROM), before 37 weeks of pregnancy is known as preterm premature rupture of membranes (PPROM). This occurs in about 3% of pregnancies and can lead to serious complications if labor doesn’t start soon. After 37 weeks, leaking fluid is a normal part of the labor process. But how long can you safely leak fluid and wait for labor to begin? Here’s what you need to know:
What is PPROM?
PPROM occurs when the amniotic sac leaks or ruptures before 37 weeks of pregnancy. The biggest risks are:
- Infection – Bacteria can move up from the vagina into the uterus, leading to chorioamnionitis, a serious infection of the fetal membranes.
- Cord compression – Without enough amniotic fluid, the umbilical cord can be compressed, cutting off blood flow and oxygen to the baby.
- Preterm birth – Ruptured membranes often leads to preterm labor.
PPROM complicates about 3% of pregnancies and is responsible for about one third of preterm births. The earlier it occurs in pregnancy, the more dangerous it can be. Ruptured membranes at 23-24 weeks have a 40-70% risk of serious complications like sepsis, cord accident, respiratory distress syndrome or intraventricular hemorrhage in the newborn.
Causes of PPROM
The causes of PPROM are not fully understood. Risk factors include:
- Infection – Bacteria ascending into the uterus can weaken fetal membranes and cause them to rupture early.
- Smoking
- Drug use
- Physical injury or trauma
- Nutritional deficits like low vitamin C
- Excess amniotic fluid (polyhydramnios)
- Genital tract abnormalities
- Cervical insufficiency
- Placental abruption
- Multiple gestation pregnancy
In about half of cases, no cause is identified. Genetic factors may play a role in weakening the fetal membranes.
Signs of PPROM
The main sign of PPROM is leaking fluid from the vagina. This fluid will be either a slow trickle or a sudden gush. Other signs include:
- Visible pooling of clear fluid in the vagina when lying down
- Soaking through a sanitary pad
- Lower back pain or mild abdominal cramping
- Change in the nature of vaginal discharge – watery instead of mucousy
Diagnosis is made by visually confirming pooling fluid in the vagina and testing the fluid to confirm it is amniotic fluid rather than urine or other discharge. Testing the fluid’s pH and looking for fetal cells like squames under a microscope can confirm ruptured membranes. Amniotic fluid has a pH of 7 or higher.
How Long Can You Leak Amniotic Fluid Before Labor?
If you experience signs of ruptured membranes before 37 weeks, you should be assessed right away to determine next steps. The longer you leak fluid, the higher the risks.
Here are general guidelines on duration of PPROM before delivery:
- Less than 24 weeks gestation – With ruptured membranes this early, there is a very high risk of serious complications. Most providers will recommend delivery as soon as the mother’s condition is stable, regardless of amniotic fluid volume.
- 24-34 weeks gestation – If amniotic fluid volume is still adequate, pregnancy may be prolonged with careful monitoring. But delivery is often recommended within 1-2 weeks.
- After 34 weeks – Delivery within hours or days is typical once PPROM occurs after 34 weeks.
Prolonging pregnancy for days or weeks with PPROM requires very careful inpatient monitoring for infection and fetal distress. Broad spectrum IV antibiotics like Ampicillin and Erythromycin are given to reduce infection risk. Steroids like Betamethasone may be given to speed fetal lung development before delivery. Fetal heart rate monitoring helps identify cord compression or distress. With careful monitoring and management, it is sometimes possible to prolong pregnancy 3-4 weeks after PPROM occurs.
But in most cases, providers aim to deliver within 1-2 weeks of PPROM between 24-34 weeks gestation. The longer you leak fluid, the higher the risks become.
Term PROM
After 37 weeks gestation, ruptured membranes is known as term PROM. This occurs in about 8-10% of pregnancies, often signalling the start of labor.
Guidelines for labor induction after term PROM are:
- If GBS negative – Induce within 24 hours
- If GBS positive – Induce immediately, within 12 hours
Expectant management for days or weeks is not recommended in term PROM due to high infection risks. Most providers will induce labor right away or within 24 hours at the latest.
When to Seek Urgent Care
Any suspected rupture of membranes before 37 weeks requires prompt evaluation. Call your provider right away or go to labor and delivery triage if you notice:
- Sudden gush of fluid from the vagina
- Persistent leakage of fluid
- Change in nature of vaginal discharge
- Lower back pain or cramping
- Fever, chills, foul-smelling vaginal discharge
With term PROM close to the due date, it is less urgent but you should still call your provider to discuss next steps. Go to L&D triage right away with any concerns like lack of fetal movement, vaginal bleeding, fever or chills.
Do not wait days or weeks to be evaluated if you suspect ruptured membranes at any point in pregnancy. Prompt diagnosis and monitoring are essential for the health of both mother and baby.
How Does Leaking Fluid Cause Labor?
After membranes rupture, prostaglandins in the amniotic fluid can trigger uterine contractions. Leaking fluid also reduces the amniotic fluid cushion around the baby, allowing the baby’s head to press down on the cervix more directly. This helps efface and dilate the cervix to start labor.
That’s why labor often begins shortly after membranes rupture near term. Some other ways PROM may kickstart labor include:
- Removal of physical barrier between amniotic fluid and myometrium allows prostaglandins direct access to uterus
- Reduced amniotic fluid and descending fetal head provide direct pressure on cervix
- Subclinical infection of amniotic fluid can stimulate release of inflammatory cytokines
- Placental separation from membranes rupturing reduces anti-labor progesterone levels
In most cases, regular contractions begin within 24 hours of membranes rupturing at term. But it’s important not to wait too long for labor, due to increased infection risk with longer duration of ruptured membranes. This is why induction is recommended within 24 hours of term PROM.
Can You Prevent PPROM?
While the causes of PPROM are not fully understood, some things may help reduce your risk:
- Practice good hygiene and treat any vaginal infections promptly
- Avoid smoking, drug use, and excess alcohol
- Maintain good nutrition before and during pregnancy
- Use progesterone supplements if you have a short cervix
- Avoid overdistending uterus with multiples or polyhydramnios
- Avoid physical trauma to the abdomen
But keep in mind that PPROM can’t always be prevented. Follow your provider’s recommendations for serial ultrasounds to monitor amniotic fluid levels and cervical length. Report any leakage of fluid or warning signs immediately so appropriate care can be provided.
Can PPROM Be Treated?
Once membranes have ruptured, there is no way to repair or close them again. Management focuses on monitoring and prevention of complications. Some key aspects of PPROM treatment include:
- Antibiotics – IV antibiotics like Ampicillin and Erythromycin reduce the risk of intrauterine infection, which is a serious complication of PPROM.
- Steroids – Steroid shots help speed development of the baby’s lungs and reduce respiratory complications.
- Magnesium sulfate – This neuroprotective medication given before preterm birth helps reduce the risk of cerebral palsy.
- Amnioinfusion – Flushing saline into the uterus can help replace some lost amniotic fluid and reduce cord compression.
- Fetal monitoring – Monitoring helps detect signs of infection or fetal distress so delivery can occur when necessary.
- Avoiding vaginal exams – Vaginal exams increase infection risk and are avoided until induction or active labor begins.
The only cure for PPROM is delivery. But with supportive care, pregnancy may often be prolonged for days or weeks to reduce risks of prematurity.
Conclusion
Rupture of membranes before term is a serious complication of pregnancy requiring prompt evaluation. Most providers recommend delivery within 1-2 weeks of PPROM between 24-34 weeks gestation due to high risks of infection and other complications. After 34 weeks, delivery within 24 hours is standard.
Careful monitoring and treatments like antibiotics and steroids may allow some gain of time before delivery. But leaking amniotic fluid leaves both mother and baby vulnerable to potentially serious health impacts. Contact your provider right away if you experience any leakage of fluid before 37 weeks. Prompt care is crucial for the best outcomes.