If your doctor or midwife says you have low amniotic fluid, it’s totally normal to feel concerned. That watery cushion around your baby feels important—and it is! But low fluid doesn’t always mean something is wrong. In many cases, it just means your healthcare team will monitor you and your baby a bit more closely.
Let’s break it down: what amniotic fluid does, what causes it to run low, how it’s diagnosed, treated, and—yes—what you can do to help.
What is amniotic fluid—and why is it so important?
Amniotic fluid is the clear, slightly yellowish liquid that surrounds your baby during pregnancy. It’s made up of water from your body early on and later includes your baby’s urine (yes, really!).
- Amniotic fluid plays a big role in helping your baby grow and develop. It:
- Cushions and protects your little bean from bumps or pressure
- Keeps the umbilical cord from being compressed
- Helps develop your baby’s lungs and digestive system
- Allows for free movement, which helps muscles and bones grow strong
- Keeps a stable temperature in the womb
In a healthy pregnancy, amniotic fluid increases until around 36 weeks, then slightly decreases as you approach your due date.
What does it mean to have low amniotic fluid?
Low amniotic fluid is a condition called oligohydramnios. It means there’s less fluid than expected for your stage of pregnancy.
How is low amniotic fluid diagnosed?
Doctors typically diagnose low fluid based on an ultrasound measurement. The most common methods are:
- Amniotic Fluid Index (AFI): Measures the depth of fluid in four parts of the uterus and adds them up. An AFI less than 5 centimeters is considered low.
- Maximum (or single) Vertical Pocket (MVP): Measures the deepest visible fluid pocket. Less than 2 centimeters is considered low.
The diagnosis matters because amniotic fluid protects your baby and supports vital systems. Too little of it—especially earlier in pregnancy—can sometimes lead to complications. But if it’s caught late in pregnancy and your baby is otherwise healthy, it may not be a major concern.
What causes low amniotic fluid?
There are several possible causes of low amniotic fluid:
- Leaking or ruptured membranes: If your water breaks early or there’s a small leak, fluid can slowly drain.
- Placental issues: If the placenta isn’t supplying enough nutrients or oxygen, baby may produce less urine (a key part of amniotic fluid).
- Certain health conditions: High blood pressure, diabetes, or dehydration in the parent can affect fluid levels.
- Post-term pregnancy: After 41 weeks, amniotic fluid naturally begins to decline.
- Foetal complications: In rare cases, problems with the baby’s kidneys or urinary tract may reduce fluid production.
- Medications: Certain drugs (like ACE inhibitors) have been linked to low fluid in early pregnancy.
How do I know if I have low amniotic fluid?
You may not feel any different if your fluid is low. Most people don’t notice symptoms. But sometimes, there are clues.
Low Amniotic Fluid Symptoms
- Leaking fluid (a trickle or gush that doesn’t smell like urine)
- A uterus that measures smaller than expected
- Feeling fewer baby movements
Because symptoms are often subtle, low fluid is usually diagnosed during a routine ultrasound or after checking your belly measurements at a prenatal appointment.
How is low amniotic fluid diagnosed?
Your healthcare provider will use ultrasound to assess the amount of amniotic fluid. If the fluid level is low, they’ll also check on your baby’s growth, movement, and overall wellbeing.
Additional tests may include:
- Non-stress test (NST): Monitors baby’s heart rate in response to movement.
- Biophysical profile (BPP): Combines an NST with an ultrasound to check baby’s breathing, movement, tone, and fluid levels.
- These tests help guide your care plan and determine if further treatment is needed.
How is low amniotic fluid treated?
Treatment depends on how far along you are and how low the fluid is. Options may include:
- Hydration: Sometimes, increasing your fluid intake (by mouth or IV) can help improve levels—especially if dehydration is a factor.
- Monitoring: If baby is healthy and you’re near full term, your healthcare provider might simply keep a close eye with more frequent ultrasounds and NSTs.
- Amnioinfusion: If you’re in labour and the fluid is very low, doctors may introduce sterile fluid into the uterus through a catheter. This can cushion the baby and reduce stress on the umbilical cord.
- Delivery: If fluid levels are dangerously low or your baby is in distress, your healthcare provider may recommend inducing labor or a c-section—especially after 37 weeks.
Can you increase amniotic fluid naturally?
In some cases, yes! Here’s what might help:
- Drink more water: Staying well hydrated may boost amniotic fluid levels, especially later in pregnancy. Aim for at least 8 to 10 glasses of water a day.
- Rest and lie on your side: Resting (especially on your left side) may improve blood flow to the uterus, which supports placental function.
- Manage health conditions: Keeping high blood pressure or gestational diabetes under control can help maintain fluid balance.
- Follow your healthcare provider’s plan: Monitoring and follow-up are key! Your healthcare provider may suggest more ultrasounds, NSTs, or other tests to keep track of things.
What are potential complications of low amniotic fluid?
While not all cases of low amniotic fluid are dangerous—especially if they occur late in pregnancy and baby is doing well—it can increase the risk of complications in some situations. That’s why your healthcare provider takes this diagnosis seriously and monitors you and your baby closely.
Possible risks of low amniotic fluid include:
- Restricted foetal growth: Amniotic fluid plays a role in cushioning and supporting healthy movement. When there isn’t enough, it may limit baby’s ability to move freely, which can affect muscle and skeletal development or lead to intrauterine growth restriction (IUGR).
- Cord compression: With less fluid, the umbilical cord can become pinched, reducing oxygen and nutrient flow to your baby. This can lead to changes in baby’s heart rate and foetal distress.
- Preterm birth or induction: If fluid levels become dangerously low, especially earlier in the third trimester, your healthcare healthcare provider may recommend early delivery to protect your baby’s health. This can raise the risk of prematurity and associated complications.
- Stillbirth: In rare cases, severely low fluid—particularly when combined with other complications like placental problems—can increase the risk of stillbirth. That’s why extra monitoring (like NSTs and biophysical profiles) is so important if oligohydramnios is diagnosed.
- Complications during labour: Low fluid can make vaginal delivery more challenging. For example, your baby might not tolerate contractions well, or the umbilical cord could become compressed during labour. In these cases, a caesarean birth may be recommended.
- That said, every pregnancy is unique. Some people with mild oligohydramnios, especially near term, go on to deliver healthy babies with no complications at all. The key is careful monitoring and a care plan tailored to your situation.
When should I call my healthcare provider?
Always reach out if you:
- Notice leaking fluid or a sudden gush
- Feel significantly fewer baby movements
- Just feel like something’s off
Even if it turns out to be nothing, your peace of mind is worth it—and your healthcare provider will want to check in just to be safe!
Hearing “low amniotic fluid” might feel scary, but with close monitoring and the right care, many people with oligohydramnios go on to have healthy pregnancies and deliveries! The key is communicating with your care team, staying on top of antenatal visits, and being aware of your body.
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REFERENCES
- Cleveland Clinic: Amniotic Fluid: Colour, Smell, Function & Disorders, October 2024
- Cleveland Clinic: Oligohydramnios — Causes, Symptoms, Diagnosis & Prevention, March 2024
- MSD Manuals: Oligohydramnios — Gynaecology and Obstetrics, March 2024
- Foetal Medicine Foundation: Oligohydramnios — Foetal Abnormalities/Amniotic Fluid
- MSD Manuals: Oligohydramnios — Gynaecology and Obstetrics
- American College of Obstetricians and Gynecologists: Indications for Outpatient Antenatal Foetal Surveillance, Obstetrics & Gynaecology, June 2021
- International Society of Ultrasound in Obstetrics and Gynaecology: Oligohydramnios — Patient Information, March 2025
