Polyhydramnios (polyhydramnion, hydramnios) is a medical condition describing an excess of
amniotic fluidin the amniotic sac. It is seen in 0.5 to 2% of pregnancies.Fact|date=November 2007 It is typically diagnosed when the amniotic fluid exceeds 2000 mL.Fact|date=August 2008
The opposite to polyhydramnios is
oligohydramnios, a deficiency in amniotic fluid.
A single case of polyhydramnios may have one or more causes. About 20% of cases are due to maternal
diabetes mellitus, which causes fetal hyperglycemiaand resulting polyuria(fetal urine is a major source of amniotic fluid). About another 20% of cases are associated with fetal anomalies that impair the ability of the fetus to swallow (the fetus normally swallows the amniotic fluid). These anomalies include:
gastrointestinalabnormalities such as esophageal atresia, duodenal atresia, facial cleft, neck masses, and tracheoesophageal fistula
*chromosomal abnormalities such as Down's syndrome and Edwards Syndrome (which is itself often associated with GI abnormalities)
*neurological abnormalities such as
anencephaly, which impair the swallowing reflex
In a multiple gestation pregnancy, the cause of polyhydramnios usually is twin-twin transfusion syndrome.
It can also be caused by some systemic medical conditions in the mother, including
Additionally, chorioangioma of the placenta can also cause this condition.
Fetuses with polyhydramnios are at risk for a number of other problems including
cord prolapse, placental abruptionand perinatal death. At delivery the baby should be checked for congenital abnormalities.
In some cases,
amnioreductionhas been used in response to polyhydramnios.cite journal |author=Piantelli G, Bedocchi L, Cavicchioni O, "et al" |title=Amnioreduction for treatment of severe polyhydramnios |journal=Acta bio-medica : Atenei Parmensis |volume=75 Suppl 1 |issue= |pages=56–8 |year=2004 |pmid=15301292 |doi=]
Amniotic fluid index
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