Table of ContentsView AllTable of ContentsDevelopmentFunctionComplications
Table of ContentsView All
View All
Table of Contents
Development
Function
Complications
Amniotic fluid is a clear to slightly yellow liquid that cushions a fetus within the amniotic sac. The developing fetus floats in amniotic fluid for the duration of a pregnancy.
At around 34 weeks gestation, roughly 800 milliliters (mL) of amniotic fluid surround the fetus. At a full-term pregnancy of 40 weeks gestation, roughly 600 mL of amniotic fluid remain.
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Amniotic fluid is present at the formation of the amniotic sac. This is a thin-walled sac that contains the fetus during pregnancy.
The development of amniotic fluid is broken into two stages:
Amniotic fluid is made up of 98% water and electrolytes, along with peptides, carbohydrates, and signaling molecules. The remaining 2% is made up of lipids and hormones.
Amniotic fluid serves a number of purposes during pregnancy, primarily to protect the fetus from harm. The functions of the amniotic fluid include:
Complications related to amniotic fluid can occur when there is too much or too little fluid.
Oligohydramnios
Oligohydramnios occurs when there is too little amniotic fluid surrounding the fetus during pregnancy. This occurs in about 4% of pregnancies.
On average, pregnant people have roughly 0.5 quart to 1 quart (500 to 1000 mL) of amniotic fluid. Too little amniotic fluid can cause problems with the development of the fetus as well as pregnancy complications.
Oligohydramnios can occur for a number of reasons. Either not enough amniotic fluid is being made, or there are issues causing the amount of amniotic fluid to decrease.
Possible causes include:
Symptoms of oligohydramnios may vary between pregnant people and may also present as symptoms of other conditions. A healthcare provider will be able to provide a conclusive diagnosis.
Possible symptoms include:
Oligohydramnios may be diagnosed following an ultrasound. A Doppler flow study, a special type of ultrasound, may be used to check blood flow through the fetus' kidneys and the placenta.
Treatment for oligohydramnios is focused on continuing the pregnancy for as long as is safe while keeping the parent comfortable.
This may involve:
Polyhydramnios
Also called hydramnios, polyhydramnios occurs when there is too much amniotic fluid surrounding the fetus. When this happens, the uterus is much larger than normal.
This is a rare condition, occurring in roughly 1% of pregnancies.
Possible symptoms of polyhydramnios include:
With most pregnancies, the exact cause of polyhydramnios is unknown.
Treatment is often not necessary in mild cases. Additional appointments may be useful to monitor the growth of the uterus. Other options include inducing labor early.
A Word From Verywell
Amniotic fluid surrounds the fetus during pregnancy and serves an important function. It protects the fetus from harm and allows for healthy development. Complications can occur when there is too much or too little amniotic fluid. If you are concerned about your pregnancy, you should speak with your healthcare provider.
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4 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Amniotic fluid.Johns Hopkins Medicine.Anatomy: fetus in utero.Mount Sinai.Amniotic fluid.Johns Hopkins Medicine.Oligohydramnios.
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Amniotic fluid.Johns Hopkins Medicine.Anatomy: fetus in utero.Mount Sinai.Amniotic fluid.Johns Hopkins Medicine.Oligohydramnios.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Amniotic fluid.Johns Hopkins Medicine.Anatomy: fetus in utero.Mount Sinai.Amniotic fluid.Johns Hopkins Medicine.Oligohydramnios.
MedlinePlus.Amniotic fluid.
Johns Hopkins Medicine.Anatomy: fetus in utero.
Mount Sinai.Amniotic fluid.
Johns Hopkins Medicine.Oligohydramnios.
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