Amniotic fluid surrounds the baby and protects it as it develops. It also helps the baby’s muscles, lungs, and digestive tract develop properly. Your healthcare provider has determined that you have too little amniotic fluid in the womb. This is called oligohydramnios. If oligohydramnios is found, it will change the way the pregnancy is managed, even if the pregnancy is otherwise healthy. Low fluid makes the pregnancy complicated. In an otherwise healthy pregnancy, the problem may not need treatment.

Pregnant woman with baby visible inside uterus. Too little amniotic fluid surrounds baby.

Causes of oligohydramnios

This condition is most common during the last trimester and in pregnancies carried beyond term. This is because amniotic fluid levels naturally decline after 41 weeks. If the problem happens earlier in pregnancy, it may be due to a health problem in the mother or fetus. If diagnosed, it would be important to determine if your waterbag has broken. Often, though, the cause of the low fluid levels is not known.

Diagnosing oligohydramnios

An ultrasound is done to measure the amount of amniotic fluid in the womb. The ultrasound uses sound waves to create detailed images of the inside of the womb. During the ultrasound test, the amount of amniotic fluid is measured, most often through a method called amniotic fluid index (AFI). Oligohydramnios is considered present if the AFI shows a fluid level less than 5 centimeters.

Managing oligohydramnios

In some cases, drinking more fluids can help increase the level of amniotic fluid. Beyond that, your health and the health of your baby is monitored. Your healthcare provider will perform regular ultrasounds to monitor your amniotic fluid level. Fetal stress tests may also be done. These tests monitor the unborn child’s health. In many cases, no treatment is needed. If your healthcare provider decides that treatment is necessary, it may include:

  • Bed rest at home or hospitalization. During this time, the health of the mother and fetus are monitored closely.

  • IV fluids. A tube put into the arm or hand is used to give the mother fluids.

  • Amnioinfusion. This increases the amount of fluid in the womb by adding (infusing) sterile saltwater (saline solution). It can only be used during labor and delivery. 

  • Induction of labor. This may be done if the pregnancy is at term or beyond. Your healthcare provider will tell you more about this if it is needed.

Follow-up care

If you or the fetus has a condition that has caused the low amniotic fluid level, the condition will be treated. Your healthcare provider can tell you more about the cause of your low amniotic fluid level. He or she can also discuss treatment choices with you.

When to seek medical care

Contact your healthcare provider right away if you have any of the following: 

  • Fever of 100.4°F (38°C) or higher

  • Sudden or severe abdominal cramping

  • Fluid leaking from the vagina

  • Regular, rhythmic contractions

  • Baby moving less than before