Low Amniotic Fluid in Pregnancy - Causes Complications and Treatment of Oligohydramnios

Low Amniotic Fluid in Pregnancy - Causes Complications and Treatment of Oligohydramnios

Pregnancy is a time full of joy and wonder. After all, you are gonna be a mom and it’s an overwhelming time in a woman’s life. But sometimes all good things come at a price. There are women who feel plenty of complications during the pregnancy. We will discuss one such common complication in this article.


Oligahydramnios is a medical term which refers to low amniotic fluid volume during pregnancy. Most of us must have heard about amniotic fluid. It’s a fluid filled in a sac that surrounds the baby in the uterus during pregnancy. The fluid is produced from the combination of baby’s urine and secretion from the lungs. It starts emerging when pregnancy reaches halfway and begin to reduce after the 36th week of pregnancy.

While amniotic fluid volume can vary, there are two extremes sides:

  • Too much fluid volume known as Polyhydramnios
  • Too little fluid volume known as Oligohydramnios

What should be the ideal amniotic fluid volume?

The amniotic fluid volume increases as pregnancy progresses and start declining after it reaches its highest point i.e. around 36 weeks of pregnancy. Normal amniotic fluid level through pregnancy can be divided into three stages:

  • 12 weeks pregnancy: 60 ml
  • 16 weeks pregnancy: 175 ml
  • 34-38 weeks pregnancy: 400-1200 ml

Why amniotic fluid is important?

Amniotic fluid is composed of constituents such as immune system cells, hormones, antibodies, nutrients and baby’s urine, which together performs a variety of jobs.

  • Providing watery cushion and preventing the baby from any trauma
  • It keeps constant temperature inside the womb
  • Prevents umbilical cord from becoming compressed
  • Helps in the development of baby’s lungs
  • Act as a protective shield against infection
  • Allows the baby to float around helping his/her bones and muscles develop properly

Also Read

Inflammation of Fetal Membranes in Pregnancy - Learn More About Intra-amniotic Infection
Inflammation of Fetal Membranes in Pregnancy - Learn More About Intra-amniotic Infection

What causes Oligohydramnios or Low Amniotic Fluid?

Experts cannot always determine the exact cause but there can be few potential reasons that can lead to low levels of amniotic fluid. The problem could occur from both mother and baby’s side. They are:



  • Problem with baby’s kidneys
  • Placental insufficiency which can create growth restriction
  • Crossing the due date of delivery (post-term)

How common is the condition of low amniotic fluid?

The condition can occur anytime during the course of pregnancy. However, low amniotic fluid is often seen in the third trimester. If a pregnant woman has passed her due delivery date by 2 weeks or more, the risk of low amniotic fluid increases. The fluid level can reduce to half after 42 weeks of pregnancy.

About 8 percent women experience low levels of amniotic fluid. The condition can cause complications in about 12 percent of cases that crosses 41 weeks of pregnancy.

Symptoms of low amniotic fluid

The lack of amniotic fluid hinders the proper growth of the developing fetus. There are few signs and symptoms which can raise suspicion of low amniotic fluid. These include:

Can we determine amniotic fluid leakage on our own?

Sometimes it could be difficult for a pregnant woman to determine whether the fluid is amniotic, vaginal or urine. The following pointers can help you determine and call for doctor’s help.

  • Amniotic fluid can be clear, white marked or have blood/mucus tinge. It is odorless and might deeply soak your underwear
  • Where vaginal fluid is yellow or white in color, urine typically have an odor
  • Another method to differentiate between amniotic fluid and urine is to put a sanitary pad in your underwear and after 30 minutes to 1 hour, examine the fluid. If it is not yellow in color, it might be amniotic fluid

Complications of low amniotic fluid

Amniotic fluid leakage, the classic sign of oligohydramnios can cause several complications, especially during the first and second trimester including:

During the third trimester, the complications due to amniotic fluid can be:

Also Read

Too Much Amniotic Fluid in Pregnancy - Causes and Complications of Polyhydramnios
Too Much Amniotic Fluid in Pregnancy - Causes and Complications of Polyhydramnios

How low amniotic fluid is diagnosed?

Usually, doctors use an ultrasound test to determine the low levels of amniotic fluid as well as abnormal kidney development of the fetus. The best way of doing this is to check for deep pocket measurement. The calculations are performed in two ways:

  • Amniotic Fluid Index - If amniotic fluid index or volume is less than 5 cm, then you have low amniotic fluid
  • Maximum Vertical Pocket - If depth of amniotic fluid is less than 2 cm, then it too indicates low level

What are the available treatment options? 

In case of low level of amniotic fluid, the doctor will closely monitor your condition. The treatment will depend on how far your pregnancy has reached and health of you and your baby or whether you have other complications.


In most of the cases, usually in the second and third trimester, amnioinfusion is used. In this procedure, fluid is infused into the womb to keep it hydrated. Though this added fluid doesn’t contain the same antibodies and hormones as in mother’s amniotic fluid, it cushions the baby and helps it to develop. However, the fluid infusion can elevate the chances of infection and might not be enough to help lung development of the baby.

Intravenous hydration

Maternal oral or intravenous hydration can help normalize amniotic fluid levels.

Induced labor

If there are low levels of amniotic fluid post-term or when the woman crosses the due date, most doctors will perform induced labor to deliver the baby.

Cesarean delivery

If the baby seems to be developed enough to be born and the amniotic fluid is low, the doctors will likely to perform the c-section delivery.

Prevention of low amniotic fluid

How can a woman prevent the condition of low amniotic fluid level? This could be the question arising in your mind. If the doctor suspects that the cause of low amniotic fluid is dehydration, he would advise the mother to take rest and drink lots of fluids.

Dehydration is a common problem in summers, so this is a general recommendation by most of the practitioners. A routine visit to the gynecologist is the key to avoid complications arising from low amniotic fluid.


1. Low Amniotic Fluid Levels: Oligohydramnios (2017, May 26). American Pregnancy Association read more
2. Oligohydramnios (2013, June). March of dimes read more