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Polyhydramnios
Polyhydramnios occurs when too much amniotic fluid builds up during pregnancy. It is also called amniotic fluid disorder, or hydramnios.
Considerations
Amniotic fluid is the liquid that surrounds the baby in the womb (uterus). It comes from the baby's kidneys, and 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 baby to move in the womb, promoting muscle and bone growth
- Helps 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
Causes
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
Duodenal atresia
Duodenal atresia is a condition in which the first part of the small bowel (the duodenum) has not developed properly. It is not open and cannot allo...
ImageRead Article Now Book Mark ArticleEsophageal atresia
Esophageal atresia is a disorder of the digestive system in which the esophagus does not develop properly. The esophagus is the tube that normally c...
ImageRead Article Now Book Mark ArticleGastroschisis
Gastroschisis is a birth defect in which an infant's intestines are outside of the body because of a hole in the abdominal wall.
ImageRead Article Now Book Mark ArticleDiaphragmatic hernia
A diaphragmatic hernia is a birth defect in which there is an abnormal opening in the diaphragm. The diaphragm is the muscle between the chest and a...
ImageRead Article Now Book Mark Article -
Brain and nervous system problems, such as
anencephaly
and myotonic dystrophy
Anencephaly
Anencephaly is the absence of a large part of the brain and the skull.
ImageRead Article Now Book Mark Article -
Achondroplasia
Achondroplasia
Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism.
Read Article Now Book Mark Article -
Beckwith-Wiedemann syndrome
Beckwith-Wiedemann syndrome
Beckwith-Wiedemann syndrome is a growth disorder that causes large body size, large organs, and other symptoms. It is a congenital condition, which ...
ImageRead Article Now Book Mark Article
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
Hydrops fetalis
Hydrops fetalis is a serious condition. It occurs when abnormal amounts of fluid build up in two or more body areas of a fetus or newborn. It is a ...
ImageRead Article Now Book Mark Article
Sometimes, no specific cause is found.
When to Contact a Medical Professional
Call your health care provider if you are pregnant and notice that your belly is getting large very quickly.
What to Expect at Your Office Visit
Your health care 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:
Gestational age
Gestation is the period of time between conception and birth. During this time, the baby grows and develops inside the mother's womb. Gestational ag...
- Have you come back sooner than normal to check it again
- Do an ultrasound
If your provider finds a birth defect, you may need amniocentesis to test for a genetic defect.
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 doctors can immediately check the health of the mother and baby and give treatment if needed.
References
Carlo WA. High-risk pregnancies. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 89.
Cunningham FG, Leveno KJ, Bloom SL, et al. Amniotic fluid. In: Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS, eds. Williams Obstetrics . 24th ed. New York, NY: McGraw-Hill; 2014:chap 11.
Gilbert WM. Amniotic fluid disorders. In: Gabbe SG, Niebyl JR, Simpson JL, et al, eds. Obstetrics: Normal and Problem Pregnancies . 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 33.
-
Polyhydramnios - illustration
Polyhydramnios may occur when a fetus cannot swallow a normal amount of amniotic fluid due to a gastrointestinal, neurological, or other problem.
Polyhydramnios
illustration
Review Date: 4/15/2015
Reviewed By: Irina Burd, MD, PhD, Assistant Professor of Gynecology and Obstetrics at Johns Hopkins University School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
