What Is Polyhydramnios?

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Polyhydramnios is a condition where there is excess amniotic fluid in the womb. Most cases won’t cause any serious problems for you or your baby.

If your healthcare provider diagnoses you with polyhydramnios you can expect a few extra checkups throughout your pregnancy to monitor for any signs of complications. But usually polyhydramnios isn’t a cause for concern, and some mild cases may even completely resolve on their own.

pregnant woman in hospital room

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Symptoms of Polyhydramnios

In most cases, there are no symptoms or only mild symptoms with polyhydramnios. The amniotic fluid builds up slowly and many people barely notice the excess fluid building up. Many of the mild symptoms of polyhydramnios are common in typical pregnancies and go unnoticed.

Symptoms of polyhydramnios include:

  • Difficulty breathing or shortness of breath
  • Heartburn
  • Constipation
  • Swollen ankles and feet
  • A tight feeling or pressure in your belly

Polyhydramnios can appear at any point during pregnancy. When it develops early, there are higher chances of developing more serious complications.

In more severe cases, there is the risk for:

  • Preterm labor and premature birth
  • Abnormal fetal growth or position
  • Umbilical cord prolapse
  • Bleeding after delivery
  • High blood pressure


The cause of polyhydramnios isn’t always clear. In mild cases only 17% were associated with an underlying disease.

Even though the exact cause of this condition can be difficult to know, there are a few causes that increase the risk of developing polyhydramnios.

Potential causes of polyhydramnios:

  • Genetic conditions in the baby
  • Diabetes and gestational diabetes in the mother
  • Carrying twins or multiple pregnancies
  • Anemia or low red blood cells in the baby
  • Viral infections during pregnancy such as parvovirus B19, rubella, and cytomegalovirus


Polyhydramnios is diagnosed during an ultrasound. It should be suspected if your fundal height in centimeters is more than three greater than your gestational age. Sometimes an additional ultrasound is ordered to give a more detailed evaluation of amniotic fluid volumes.

Single Deepest Pocket Measurement

Single deepest pocket measurement provides a simple approach to diagnosing polyhydramnios and is commonly used. A medical provider will use an ultrasound to view four quadrants of the womb and measure the largest pocket of fluid.

It can also be diagnosed with an amniotic fluid index (AFI) greater than or equal to 24. In calculating the AFI, the pockets are measured in all four quadrants and added together.

If the pockets are smaller than 2 centimeters then there is low amniotic fluid, and greater than 8 centimeters is considered high amniotic fluid.

Determining Severity

This method is also used to determine the severity:

  • Mild cases are between 8 to 11.9 centimeters
  • Moderate cases are between 12 to 15.9 centimeters
  • Severe cases have pockets of 16 centimeters and above


When polyhydramnios is diagnosed, your healthcare provider will likely request other tests to identify any underlying conditions.

  • An oral glucose tolerance test to rule out gestational diabetes
  • Testing for infection to rule out viral causes

Your treatment plan will depend on if any underlying conditions need to be treated. If you are diagnosed with a condition like diabetes that may be causing your increased amniotic fluid, diet changes and possibly medication will be recommended to control it.

Depending on the amount of fluid you have in your womb, you may need treatment to remove some of the excess fluid by:

  • Draining fluid through a procedure called amniocentesis. A procedure that uses a needle to remove fluid from the womb.
  • Prescribing medications to reduce amniotic fluid. Prostaglandin synthetase inhibitors can be used during the first two trimesters, but it is not recommended after the 28th week of pregnancy to reduce amniotic fluid. Indomethacin is a nonsteroidal anti-inflammatory drug that can be used to treat polyhydramnios and is not used at 32 weeks or later.

People diagnosed with polyhydramnios can expect more careful monitoring of fetal development, position, and amniotic fluid volume.

Labor and Delivery

It’s recommended that pregnant people diagnosed with polyhydramnios give birth in a hospital. This allows easy access to medical attention if any complications develop while giving birth or during labor.

Most people can wait to naturally go into labor and have a vaginal delivery. If your healthcare provider determines there is an increased risk to you or your baby, your practitioner may recommend inducing labor with medicine or a cesarean section (C-section).

Your water may break early because of the increased pressure of the excess fluids. And you’ll likely pass a larger than average volume of fluid when your water does break, but this is to be expected.

After delivery, your baby will have an examination and normal testing to ensure they are healthy.


If you’ve been diagnosed with polyhydramnios, try not to worry and remember that it isn’t normally a sign of any serious complications.

You can also seek social support from loved ones or others who have been diagnosed with polyhydramnios to help reduce anxiety and stress about the health of your baby.

Talk with your healthcare provider or midwife about your birthing plan and any concerns that you have. Having a plan in place in case your water breaks or you go into labor early could help you feel more comfortable.

When to Seek Emergency Care

If you have a sudden large increase in the size of your stomach, contact your healthcare provider for medical advice.

A Word From Verywell

Most people who have polyhydramnios only have mild symptoms and deliver healthy babies.

Any diagnosis during pregnancy can add anxiety and stress. Getting support from your loved ones and your healthcare team can help you navigate your pregnancy.

If you have any specific questions or concerns, contact your healthcare provider and follow their recommendations to help you deliver a healthy baby. 

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Polyhydramnios.

  2. Cleveland Clinic. Polyhydramnios.

  3. Hamza A, Herr D, Solomayer EF, Meyberg-Solomayer G. Polyhydramnios: causes, diagnosis and therapyGeburtshilfe Frauenheilkd. 2013;73(12):1241-1246. doi:10.1055/s-0033-1360163

By Ashley Braun, MPH, RD
Ashley Braun, MPH, RD, is a registered dietitian and public health professional with over 5 years of experience educating people on health-related topics using evidence-based information. Her experience includes educating on a wide range of conditions, including diabetes, heart disease, HIV, neurological conditions, and more.