Polyhydramnios

Polyhydramnios
Classification and external resources
Specialty	obstetrics
ICD-10	O40
ICD-9-CM	657
DiseasesDB	10319
MedlinePlus	003267
eMedicine	radio/566
Patient UK	Polyhydramnios
MeSH	D006831
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Polyhydramnios (polyhydramnion, hydramnios, polyhydramnios) is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in about 1% of pregnancies. It is typically diagnosed when the amniotic fluid index (AFI) is greater than 24 cm. There are two clinical varieties of polyhydramnios:

The opposite to polyhydramnios is oligohydramnios, a deficiency in amniotic fluid.

In most cases, the exact cause cannot be identified. A single case may have one or more causes, including intrauterine infection (TORCH), rh-isoimmunisation, or chorioangioma of the placenta. In a multiple gestation pregnancy, the cause of polyhydramnios usually is twin-to-twin transfusion syndrome. Maternal causes include cardiac problems, kidney problems, and maternal diabetes mellitus, which causes fetal hyperglycemia and resulting polyuria (fetal urine is a major source of amniotic fluid).

A recent study distinguishes between mild and severe polyhydramnios and showed that Apgar score of less than 7, perinatal death and structural malformations only occurred in women with severe polyhydramnios. In another study, all patients with polyhydramnios, that had a sonographically normal fetus, showed no chromosomal anomalies.

(M/C for polyhydramnio is fetal anomalies 'Williams Obstetrics, 24th Edition - Cunningham, Leveno, Bloom et al. Table 11-2) but these anomalies include:

There are several pathologic conditions that can predispose a pregnancy to polyhydramnios. These include a maternal history of diabetes mellitus, Rh incompatibility between the fetus and mother, intrauterine infection, and multiple pregnancies.

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Wikipedia