Everything You Need to Know About Amniotic Fluid - Baby Chick
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Everything You Need to Know About Amniotic Fluid

Amniotic fluid is your body's way of helping you keep your growing baby safe. Here's everything you need to know about this special liquid.

Updated March 28, 2024

by Marianella Orlando

Medically reviewed by Kristy Goodman

Obstetrician-Gynecologist Physician Assistant, MS, MPH, PA-C

When you discover the news that you’re having a baby, something inside you changes. You want to do everything you can to keep the little one growing in you safe at all costs. You want to eat the best foods possible (though we understand entirely those darn cravings get in the way of this) and get as much rest as possible. And you strive to keep your health and well-being in good hands. Fortunately, nature is on your side, working overtime to keep your baby safe. With help from a little something called amniotic fluid, your fetus is provided an extra padding of protection from exterior harm–like a bump or fall.

Amniotic Fluid: What You Should Know

But what exactly is this special liquid, and how do you know if you have enough to guard your baby? What happens if you have too little or if it begins to leak? To help you on your new mommyhood journey, we did the homework for you and created a robust guide that can help answer some of these questions.

What Is Amniotic Fluid?

Amniotic fluid is a protective liquid surrounding a baby during pregnancy and helps cushion them from bumps or sudden movements.1 The fluid is contained in the amniotic sac and provides necessary antibodies, nutrients, and hormones for a fetus’ development.

The amniotic fluid is also responsible for keeping your baby safe and helping:

  • Babies move around safely in the womb (which leads to proper bone growth and muscle development)
  • The lungs properly develop
  • Provide a steady temperature around the baby
  • Prevent pressure on the umbilical cord

The liquid begins to form just 12 days after conception and is initially filled with water. By 20 weeks of gestation, it consists of your baby’s urine—which is swallowed and excreted.

What Does Amniotic Fluid Look Like?

Healthy amniotic fluid is no different in consistency than water. It doesn’t have a sticky texture but may have a few particles floating around it that are clear, white-flecked mucus or blood. Despite this, it is odorless, so you don’t worry about there being a smell when your “water breaks.”

If your amniotic fluid is green or brown, this indicates that the baby had its first bowel movement while still in the womb, known as meconium. Meconium in the liquid, though, can be dangerous. It can lead to meconium aspiration syndrome, which occurs when meconium enters the fetus’ lungs. It may require treatment after birth to prevent breathing problems down the line.

What Are Normal Levels of Amniotic Fluid?

Throughout your pregnancy, your amniotic fluid volume will be routinely assessed. Your physician will use an ultrasound to measure the amount of liquid within your amniotic sac through a method known as the amniotic fluid index (AFI).4

The AFI measures the volume by dividing the uterus into four imaginary quadrants and reviews the fluid depth in each area, which is then added together. A sum ranging from 5 to 25 centimeters indicates a normal and healthy AFI.4 

What Are Abnormal Levels of Amniotic Fluid?

Too little or too much amniotic fluid in your womb can be dangerous for you and your baby. Below, we break down the difference between what the two abnormal levels may indicate.

Low Amniotic Fluid Levels:

An AFI lower than five centimeters is known as oligohydramnios and affects about 4 out of 100 women in the USA.2

Some signs you’re suffering from oligohydramnios are if you’re not gaining enough weight, fluid leaking from your vagina, or your baby isn’t growing as much as it should. The cause results from several factors, including a leak or rupture of membranes, pregnancy that exceeds 42 weeks, birth defects, placental dysfunction, or maternal complications (dehydration, diabetes, and preeclampsia).2

The condition can occur anytime throughout your pregnancy but commonly happens in the final trimester of gestation. This can lead to issues during labor and childbirth and may increase the chance of needing a cesarean section. The fetus may also grow slowly as a result of the condition.

If you’ve been diagnosed, treatment may include increasing the amount of amniotic fluid through amnioinfusion. This procedure is completed by inserting saline into the uterus with a catheter (thin tube) during labor. However, your healthcare provider will determine your eligibility for the treatment, depending on how far along you are in your pregnancy.

High Amniotic Fluid Levels:

On the other hand, according to the American Pregnancy Association, polyhydramnios is a condition when amniotic fluid is greater than 25 centimeters and only occurs in about 1% of pregnancies.3

This condition can happen in pregnancies with twins or triplets or in women with gestational diabetes. While the number of individuals affected by polyhydramnios is low, it can also be caused by birth defects or diabetes.

In mild cases of polyhydramnios, there are little to no symptoms present. For those that are more serious, expectant moms should look out for:

  • Heartburn
  • Constipation
  • Tightness in the belly
  • Decreased urine production
  • Problems breathing
  • Swelling of the vulva or lower extremities

Treatment for having too much amniotic fluid depends on its severity. But sometimes, your doctor may use a needle to help drain the fluid from the sac. There is also medication available that can help decrease the volume, but there are risks of the drug causing damage to your baby’s heart. If you’re concerned, contact your physician as soon as possible and discuss the options that may be available.

What are the signs that my amniotic fluid is leaking?

During your pregnancy, sometimes you may spot discharge. You may even tinkle yourself from a good laugh, a strong sneeze, or your uterus pushing up against your bladder. But three key indicators let you know your fluid is leaking.

  • Amount of leakage: A good test is to line your underwear with a pantyliner. Check to see if your pantyliner is wet each time you use the restroom over a few hours. If you notice that it’s always wet, your amniotic fluid is likely leaking.
  • Color: The fluid in your amniotic sac is a clear or yellowish hue. If you spot the clear/yellow fluid when using the bathroom that is different from the cloudy and sticky consistency of discharge and the brighter yellow of urine, make sure to contact your doctor. A brown or green fluid color signals meconium, which you should also contact your physician.
  • Scent: Amniotic fluid does not have a smell. So, if you’ve noticed some leakage or fluid trickling down there that doesn’t smell like urine and is odorless, it’s a reasonable assumption that it’s leaking.

If you have any questions or concerns about the color, odor, or volume of your amniotic fluid, contact your physician, who can help determine whether there is a problem. Be watchful of your body, as your amniotic fluid is essential to your baby’s well-being.

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Marianella Orlando was born and raised in Philadelphia. She has a Master of Science in Journalism from Columbia University. Her work has since been featured in Philadelphia Magazine, The Philadelphia… Read more

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