How to Say It: pah-lee-HI-dram-knee-ohs


Polyhydramnios is too much amniotic fluid. This fluid surrounds the unborn baby. It protects the baby and helps them grow.

Having too much of this fluid can cause problems with labor and delivery. The extra fluid may also stunt fetus growth.

Fetus in Utero, Amniotic Fluid

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The cause is not always known. It may be due to decreased swallowing or increased urination in the fetus.

Risk Factors

Things that may raise the risk of polyhydramnios are:

  • Defects in the fetus development
  • Rh disease—mother and baby have different blood types
  • Diabetes in the mother
  • Pregnancy with identical twins


Symptoms may not occur with mild changes. When symptoms appear, they may include:

  • Belly discomfort
  • Trouble breathing due to pressure on the lungs


Signs of polyhydramnios are often found during regular prenatal screening. The doctor will use an ultrasound to:

  • View the uterus and fetus
  • Check fluid levels
  • Look for problems in the fetus
  • Look for possible causes


Treatment depends on how severe the condition is. Mild changes may resolve on their own. The doctor will watch and test for changes over time.

If the condition continues or causes problems, options may be:

  • Delivering the baby
  • Removing excess fluid through a needle
  • Giving medicine to reduce fluid


This condition cannot always be prevented. Proper care before and during pregnancy may help lower the risk.


American Pregnancy Association
The American Congress of Obstetricians and Gynecologists


Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada


Amniotic fluid abnormalities. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/amniotic-fluid-abnormalities#POLYHYDRAMNIOS. Accessed January 21, 2021.
Polyhydramnios. March of Dimes website. Available at:
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Accessed January 21, 2021.
Polyhydramnios. The Fetal Medicine Foundation website. Available at: https://fetalmedicine.org/education/fetal-abnormalities/amniotic-fluid/polyhydramnios. Accessed January 21, 2021.
Prenatal ultrasound screening. EBSCO DynaMed website. Available at: https://www.dynamed.com/evaluation/prenatal-ultrasound-screening. Accessed January 2021.
Wolf F, Peleg M,et al. Isolated polyhydramnios in the third trimester: is a gestational diabetes evaluation of value? Gynecol Endocrinol. 2017 Nov;33(11):849-852.
Last reviewed January 21, 2021 by Mary Beth Seymour, RN
Last Updated: 1/21/2021

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