What is polyhydramnios?
Polyhydramnios is when you have too much amniotic fluid during pregnancy. Amniotic fluid is the liquid that surrounds the fetus in your uterus. Amniotic fluid plays a significant role in the fetus's growth and development.
This condition usually happens in the second half of pregnancy, but it may occur as early as 16 weeks into pregnancy. Mild polyhydramnios doesn’t usually cause complications. Your pregnancy care provider will monitor you closely in case your condition worsens and treatment is necessary.
How common is polyhydramnios?
Polyhydramnios is rare and affects about 1% of pregnancies.
Symptoms and Causes
What are the signs and symptoms of polyhydramnios?
Some people don’t experience any symptoms because the condition is mild. If you have a more severe case of polyhydramnios, you could have these symptoms:
- Sensation of tightness in your stomach, cramping or contractions.
- Shortness of breath.
- Difficulty pooping (constipation).
- Peeing more often.
- Swelling in your vulva (external genitals), legs and feet.
When your uterus gets larger, it puts pressure on nearby organs like your lungs, stomach, rectum and bladder. This added pressure is typically the cause of your symptoms.
Your pregnancy care provider may suspect you have too much amniotic fluid if:
- Your uterus measures larger than expected for the gestational age of the pregnancy.
- They’re having difficulty finding a fetal heartbeat.
- They can’t feel the fetus's position in your uterus.
What is the most common cause of polyhydramnios?
For most people (especially people with mild cases), the cause of polyhydramnios is unknown.
Moderate to severe polyhydramnios could be caused by the following:
- The fetus can’t swallow amniotic fluid due to a congenital disorder.
- High blood glucose levels (caused by diabetes before or after becoming pregnant).
- Carrying identical twins with twin to twin transfusion syndrome (TTTS).
- Differing Rh factor (you’re Rh-negative and the fetus is Rh-positive).
- Complications with the fetal heart rate.
- The fetus has an infection.
Diagnosis and Tests
How is polyhydramnios diagnosed?
Your pregnancy care provider will measure your abdomen (a measurement called fundal height) to determine if your uterus is too large. Typically, that means you’re measuring two or more weeks ahead of your expected due date.
They’ll use an ultrasound to measure how much amniotic fluid is in your uterus. There are two ways to do this: amniotic fluid index (AFI) and maximum vertical pocket (MPV). AFI checks how deep the fluid is in four areas of your uterus. Your provider adds these numbers up. MPV measures only the deepest area of your uterus to check for fluid volume. If one of these tests shows you have polyhydramnios, your provider will likely order additional tests to check for congenital disorders, diabetes or other conditions. Some of these tests may include:
- Fetal echocardiogram (a stronger ultrasound that can see the fetus's circulatory system).
- Nonstress test (to check for abnormalities in the fetal heart rate).
- Biophysical profile (checks the fetus's tone, movement and breathing motions).
- Amniocentesis (a test that diagnoses certain congenital disorders).
- Glucose challenge test (a test that checks for gestational diabetes).
Management and Treatment
How is polyhydramnios treated?
Polyhydramnios is generally not treated if it’s a mild case or if you’re at the end of your pregnancy. Your provider may schedule additional appointments to monitor your condition. In most cases, monitoring your pregnancy closely is the best plan.
Treatment may be needed if you have severe polyhydramnios. In some cases that means treating the underlying condition (like diabetes) causing polyhydramnios. Other treatment options include:
- Draining excess amniotic fluid.
- Inducing labor before your due date, usually between 37 and 39 weeks of pregnancy.
What are the dangers of having polyhydramnios?
Too much amniotic fluid in your uterus puts pressure on your nearby organs and causes pregnancy complications. The condition is usually more serious if it occurs early in pregnancy because there’s more time for amniotic fluid to continue to build up. The excess fluid itself is not harmful to the fetus.
Other complications of too much amniotic fluid include:
Can I prevent polyhydramnios?
No, you can’t prevent polyhydramnios. If you’ve been diagnosed with gestational diabetes or had diabetes before pregnancy, managing your blood sugar levels is one precaution you can take.
Outlook / Prognosis
What can I expect if I have this condition?
People with polyhydramnios may be monitored more closely for the remainder of the pregnancy. You can expect more frequent appointments as well as more ultrasounds to measure amniotic fluid volume.
Your birthing experience shouldn’t be too different than someone without polyhydramnios. Your baby’s heartbeat will be evaluated during labor to make sure they aren’t going through too much stress. You may also pass a large amount of amniotic fluid as you give birth. A pediatrician will evaluate your baby immediately after birth and make sure they’re healthy.
How does polyhydramnios affect my baby?
Mild cases of polyhydramnios shouldn’t affect your baby. In diabetes-related cases, the fetus may grow too large for a vaginal delivery. Severe cases of polyhydramnios may lead to premature labor and your baby being born early. If your pregnancy care provider believes your condition needs treatment, they’ll suggest the best path forward to ensure you and your baby are taken care of.
Can you have a healthy baby with polyhydramnios?
Yes, most people will not have pregnancy complications from too much amniotic fluid and will have a healthy baby.
Will I need a C-section?
You may need a cesarean section (C-section) if your provider believes a vaginal delivery is too risky. Your chances of having a C-section are only slightly increased.
What can I do to help relieve symptoms of polyhydramnios?
If you’re diagnosed with polyhydramnios, you can try to relieve your worries by doing the following:
- Try to find ways to relax.
- Rest for longer periods of time.
- Be open with your healthcare providers about how you envision your labor and birth process progressing, especially if it occurs prematurely.
- Contact your provider if you feel other symptoms occur or if your belly becomes larger quickly.
- Join an online forum to speak to others with similar issues.
When should I see my healthcare provider?
Contact your pregnancy care provider if you have any new symptoms, begin feeling overly full in your belly or notice your abdomen gets bigger suddenly. If your provider diagnoses you with any health condition during pregnancy, it’s very important to attend all your prenatal appointments and ultrasounds. Ask them what you can expect if you have polyhydramnios, so you can call them if you believe your condition is worsening.
A note from Cleveland Clinic
Polyhydramnios is a complication of pregnancy that typically doesn’t require treatment. Your provider will watch you closely and may recommend an induction. If you’ve been diagnosed with having too much amniotic fluid, it’s OK to be concerned. Talk to your pregnancy care provider about your concerns and ask any questions you have about the condition. Your provider is there to support you and make sure you and your baby are healthy. Most people with polyhydramnios have healthy babies without complications.
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