Polyhydramnios Overview
Learn About Polyhydramnios
Polyhydramnios occurs when too much amniotic fluid builds up during pregnancy. It is also called amniotic fluid disorder, or hydramnios.
Pregnancy - polyhydramnios; Hydramnios - polyhydramnios
Amniotic fluid is the liquid that surrounds the baby in the womb (uterus). It comes from the baby's kidneys and developing urinary system, and then it goes into the uterus from the baby's urine. The fluid is absorbed when the baby swallows it and through breathing motions.
While in the womb, the baby floats in the amniotic fluid. It surrounds and cushions the infant during pregnancy. The amount of amniotic fluid is greatest at 34 to 36 weeks of pregnancy. Then the amount slowly decreases until the baby is born.
The amniotic fluid:
- Allows the baby to move in the womb, promoting muscle and bone growth
- Helps the baby's lungs to develop
- Protects the baby from heat loss by keeping the temperature constant
- Cushions and protects the baby from sudden blows from outside the womb
Polyhydramnios can occur if the baby does not swallow and absorb amniotic fluid in normal amounts. This can happen if the baby has certain health problems, including:
- Gastrointestinal disorders, such as duodenal atresia, esophageal atresia, gastroschisis, and diaphragmatic hernia
- Brain and nervous system problems, such as anencephaly and myotonic dystrophy
- Achondroplasia
- Beckwith-Wiedemann syndrome
- Fetal viral or bacterial infections
It can also happen if the mother has poorly-controlled diabetes.
Polyhydramnios also may occur if too much fluid is produced. This may be due to:
- Certain lung disorders in the baby
- Multiple pregnancy (for example, twins or triplets)
- Hydrops fetalis in the baby
- Placental abnormalities
Sometimes, no specific cause is found.
Contact your health care provider if you are pregnant and notice that your belly is getting large very quickly.
Your provider measures the size of your belly at every visit. This shows the size of your womb. If your womb is growing faster than expected, or it is larger than normal for your baby's gestational age, the provider may:
- Have you come back sooner than normal to check it again
- Do an ultrasound of your womb
If your provider finds a birth defect, you may need amniocentesis to test for a genetic variant in your baby.
Mild polyhydramnios that shows up later in pregnancy often doesn't cause serious problems.
Severe polyhydramnios may be treated with medicine or by having extra fluid removed.
Women with polyhydramnios are more likely to go into early labor. The baby will need to be delivered in a hospital. That way, the providers can immediately check the health of the mother and baby and give treatment if needed.
Teresa Sparks is a Reproductive Medicine specialist and an Obstetrics and Gynecologist in San Francisco, California. Dr. Sparks is rated as an Elite provider by MediFind in the treatment of Polyhydramnios. Her top areas of expertise are Fetal Edema, Hydrops Fetalis, Hemolytic Disease of the Newborn, and Alpha Thalassemia.
Michael Belfort is a Neonatologist and an Obstetrics and Gynecologist in Houston, Texas. Dr. Belfort is rated as an Elite provider by MediFind in the treatment of Polyhydramnios. His top areas of expertise are Myelomeningocele, Twin-To-Twin Transfusion Syndrome, Placenta Previa, Hysterectomy, and Endoscopy. Dr. Belfort is currently accepting new patients.
Martin Komhoff practices in Marburg An Der Lahn, Germany. Mr. Komhoff is rated as an Elite expert by MediFind in the treatment of Polyhydramnios. His top areas of expertise are Bartter Syndrome, Polyhydramnios, Hyperaldosteronism, and Cerebral Hypoxia.
Summary: The goal of this study is to compare 2 medications that are commonly used to prevent excess uterine bleeding (postpartum hemorrhage, or PPH) following cesarean delivery (CD), oxytocin and carbetocin. Most of the trials evaluating the preventative role of oxytocin and carbetocin after CD have focused on patient with low-risk of PPH. This trial will focus on patients that are at increased risk of PP...
Summary: The present trial intends to assess the diagnostic accuracy of symphysis fundal height (SFH) as opposed to SFH combined with point of care ultrasound to measure the fetal abdominal circumference (POC-US-AC) in identifying small and large for gestational age infants (SGA and LGA infants) among low-risk pregnant women cared for by midwives after 35 weeks' gestation. Low risk pregnancies will be eval...
Published Date: May 22, 2025
Published By: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Acharya KK, Sprecher AJ, Cohen SS. The fetus. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 117.
Buhimschi CS, Mesiano S, Muglia LJ. Pathogenesis of spontaneous preterm birth. In: Lockwood CJ, Copel JA, Dugoff L, et al, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2023:chap 7.
Lamale-Smith LM, Pinson KA. Amniotic fluid disorders. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 9th ed. Philadelphia, PA: Elsevier; 2025:chap 28.