Amniotic Fluid: What is It and Signs of Leaking

Everything You Need to Know About Amniotic Fluid

February 13, 2019

Everything You Need to Know About Amniotic Fluid

Everything You Need to Know About Amniotic Fluid
Everything You Need to Know About Amniotic Fluid

We’ve seen it countless times in movies and on TV: camera zooms in on a very pregnant mama-to-be, panic washes over her face and whoosh! Suddenly there’s a gush of amniotic fluid at her feet as her water breaks, and labor begins.

Despite the fact that this isn’t quite the way things usually go down (but hey, it makes for a good plot twist, right?) amniotic fluid is a pretty iconic part of labor and delivery—and a hugely important part of pregnancy. But what exactly is amniotic fluid, and what does it do for baby? And how do you know if you have too much—or too little?

Let’s give one of the most essential parts of pregnancy the attention it deserves with a download on all things amniotic fluid.

What is Amniotic Fluid?

Amniotic fluid is the fluid that surrounds the baby while in the uterus. Think of it like a warm, padded home where your baby grows and develops over 40 weeks of pregnancy. It helps baby maintain a steady temperature, offers protection and cushioning, helps baby’s lungs and digestive systems develop (because your baby breathes it in and swallows it), prevents umbilical cord compression and gives baby the ability to move around and develop muscles and bones. It also contains nutrients, antibodies and hormones. It does a lot!

The amniotic sac that holds your baby forms about 12 days after conception and is at first filled with mostly water. After about 20 weeks pregnant onward, the fluid is comprised mostly of your baby’s urine.

What does amniotic fluid look like?

Amniotic fluid is clear or tinted yellow.

If it’s not, it could mean that your baby has had its first bowel movement—also called meconium—while still in the womb. (In this case, the fluid usually looks green or brown.) If this happens, your doctor will determine whether or not baby needs treatment after birth to prevent breathing problems.

What does amniotic fluid smell like?

The quick answer here: not much. Amniotic fluid is generally odorless.

What are Normal Levels of Amniotic Fluid?

Throughout your pregnancy, your healthcare provider will routinely check your amniotic fluid level to make sure it’s within a normal range. That’s because too much fluid—or too little—can lead to problems for both you and your baby.

A normal level of amniotic fluid is about one quart by 36 weeks pregnant. From 36 weeks onward, your fluid level drops until your water breaks. Your doctor will use an ultrasound to measure the amount of fluid around your baby by using the amniotic fluid index (AFI) and the maximum vertical pocket (MPV). AFI checks the depth of fluid in four areas of your uterus, while the MPV measures the fluid level in the deepest area.

Low amniotic fluid

Oligohydramnios is the condition defined by having too little amniotic fluid. Signs of this condition include:

  • Low maternal weight gain
  • Fetal growth restriction (your baby isn’t growing as fast as they should)
  • Leaking fluid from your vagina

About 8% of women can have low levels of amniotic fluid, and about 4% are diagnosed with oligohydramnios. It can be caused by a number of factors, including birth defects, placental problems, a leak or rupture of the membranes (either a gush or a slow, constant trickle), maternal complications (most commonly dehydration, preeclampsia and diabetes) or a post due date pregnancy (42+ weeks pregnant).

Being diagnosed with oligohydramnios does pose risks to your baby, especially the earlier in pregnancy that you’re diagnosed. Treatment options will depend on how far along you are, and in some cases, there are ways to increase amniotic fluid levels.

How to increase amniotic fluid

A procedure called amnioinfusion is when a saline solution is flushed into the uterus, and it’s one way to increase amniotic fluid. It’s done during labor via inserting a catheter into the uterus through the cervix, and studies show it decreases the pressure around the umbilical cord and lower the chances of cesarean delivery.

Prior to delivery, fluid injection via amniocentesis is another way to increase amniotic fluid. Although it’s been shown that fluid levels will once again drop within a week of this procedure, it can help doctors visualize the fetus via ultrasound and make a diagnosis.

And though it may sound simple, rehydrating (either by drinking lots of fluids or via an IV) has been shown to help increase amniotic fluid.

Too much amniotic fluid

On the other end of the spectrum is polyhydramnios—the condition of having too much amniotic fluid. Unlike with oligohydramnios, polyhydramnios doesn’t tend to present with many symptoms. And in about 50% of cases, no one knows what causes it. In the other cases, causes can include birth defects, an infection in the baby and/or problems with baby’s heartbeat, diabetes, twin-to-twin transfusion syndrome or a mismatch between your blood and your baby’s blood, like Rh disease.

Being diagnosed with too much amniotic fluid is less common than having too little—only about 1% of pregnant women are diagnosed with polyhydramnios. Most cases are mild and result from a gradual buildup of fluid, but the condition can increase your risk of some serious complications such as premature birth, placental abruption or stillbirth, so it’s important to never miss a prenatal checkup, especially if you’re feeling anything abnormal.

How to decrease amniotic fluid

Treatment for polyhydramnios depends on both its severity and its underlying causes. In some cases, it’s possible to use a needle to drain and decrease amniotic fluid. It’s also possible to use a medication to decrease fluid that works by lowering the amount of urine your baby produces; however, the drug does carry a risk of heart damage to your baby, so it’s very important to discuss this with your healthcare provider and receive close monitoring if this is the route you choose.

Signs of Leaking Amniotic Fluid

Let’s be honest—fluids like discharge, occasional spotting and even a little bit of pee when you laugh or sneeze can all be pretty normal parts of pregnancy. But how do you know if what you’re experiencing is normal or if you’re leaking amniotic fluid? There are a few ways to tell.

  • Color. Amniotic fluid is generally clear, while urine tends to be on the yellower side and discharge more of a cloudy white. If you’re noticing a continuous trickle or even a small gush of clear fluid, odds are you’re leaking amniotic fluid.
  • Odor. Amniotic fluid is odorless while urine smells like…well, urine. If what you’re experiencing is odorless, all signs point to amniotic fluid.
  • Amount. Is the leaking fluid continuous? Is it filling in a pantyliner in a few hours? If so, your amniotic fluid is probably leaking.

If you’re experiencing signs of leaking amniotic fluid, are unsure if what you’re seeing is urine or amniotic fluid, or are seeing fluid or discharge tinged with green, brown or blood, it’s important to reach out to your healthcare provider right away. It’s also important not to use tampons, have sex or do anything else that could introduce bacteria into the vagina.

Amniotic fluid plays such a big role in pregnancy and baby’s development.

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