Leaking amniotic fluid: signs of premature rupture of membranes

Amniotic fluid is the warm, fluid cushion that surrounds and protects the baby in the womb. 

Sometimes this fluid leaks and you and your baby are at risk.

What is leaking amniotic fluid?
There are membranes, called the amniotic sac, which hold the amniotic fluid in place. Usually, the membranes rupture during labor — a situation often called “water breaking.” Sometimes, the water breaks early before the pregnancy reaches term or the woman goes into labor. This is referred to as premature rupture of membranes (PROM), which results in leaking amniotic fluid.

When the water breaks at term, most women will go into labor on their own within 24 hours. If it breaks before the 37th week of pregnancy is completed, it is called preterm premature rupture of membranes (PPROM). The earlier the water breaks, the more serious the situation for the mother and baby.

Understanding the amniotic fluid levels
The amount of amniotic fluid tends to increase as your pregnancy progresses, and it reaches its highest point at about 36 weeks. 

• At 12 weeks gestation, the amniotic fluid is about 60 milliliters (mL)
• At 16 weeks gestation, it is about 175 mL
• Between 34 and 38 weeks gestation, it is about 400-1200 mL

Doctors measure the amniotic fluid levels using an ultrasound scan to check and calculate the amniotic fluid index (AFI) or the maximum vertical pocket (MPV). 

How to know if you’re leaking amniotic fluid
Unlike urine or vaginal fluid, amniotic fluid is clear, white-flecked, and/or tinged with mucus or blood. It has no odor and often saturates your underwear. It is unlike urine, which has an ammoniacal odor, or vaginal fluid, which is usually white or yellow.

Moreover, if it is the amniotic fluid, you’ll notice more fluids leaking when you’re lying down than when you’re standing, sitting, or walking. The reason is that when you’re upright, your baby’s head blocks the cervical opening and keeps most amniotic fluid trapped inside.

Another way to determine if the fluid is the amniotic fluid is to first empty your bladder. Then, place a sanitary pad or panty liner in your underwear; examine the fluid on the pad after 30 minutes to an hour. If the fluid has a yellow color, it’s likely urine, but if it doesn’t, the fluid could be the amniotic fluid.

Effects on the baby
Leaking amniotic fluid can be dangerous for your baby at any point during your pregnancy. When it happens during the second trimester, it can cause pregnancy loss, poor growth, birth defects, premature birth, or stillbirth.

If it happens during the third trimester, it can lead to the compression of the umbilical cord, which can affect the baby’s ability to get oxygen. This risk can necessitate a cesarean delivery.

What to do if amniotic fluid is leaking
Once you notice that you’re leaking amniotic fluid, go and see your doctor immediately. At the hospital, your doctor will do some simple tests to confirm that what you’re leaking is amniotic fluid and also examine you to know the state of your pregnancy.

Once leaking amniotic fluid is confirmed, you will stay in the hospital until your baby is delivered. However, the doctor will discuss the state of the pregnancy with you and offer you the management option that suits your stage of pregnancy.

At 37 weeks: If your pregnancy is up to 37 completed weeks, your baby is ready to be born. Your caregiver will probably recommend a watchful observation for a few hours to see if you go into spontaneous labor. If that doesn’t happen, they will recommend delivery via induction or cesarean section, depending on your history.

Between 34 and 37 weeks: Your provider will likely suggest that you be induced to avoid infection. They may also try to delay delivery to give your baby a chance to develop further, but it may be safer for the baby to be born a few weeks early than to risk infection.

Before 34 weeks: If your water breaks before 34 weeks, your doctor may try to hold off your labor by putting you on bed rest. You may be given preventive antibiotics, steroids to help the baby’s lungs grow quickly, and magnesium sulfate (if it’s before 32 weeks) to reduce the baby’s risk of neurological impairment.

Factors that increase the risk of leaking amniotic fluid

Some of the factors that may increase your risk of leaking amniotic fluid include:

• Smoking during pregnancy
• Chronic vaginal bleeding during your pregnancy
• History of previous early membrane rupture
• Bacterial vaginosis (BV)
• Some STDs
• Placental abruption
• Carrying multiples

How to prevent it

There’s no way to entirely prevent leaking amniotic fluid. However, you can lower your risk by ensuring adequate prenatal care, including keeping to antenatal appointments, eating well, and avoiding alcohol, smoking, and illicit drugs. If you previously had PPROM tell your healthcare provider for an appropriate approach.