Polyhydramnios
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- Micro-X Ltd, Shareholder (ongoing)
Updates to Article Attributes
Polyhydramnios refers to a situation where the amniotic fluid volume is more than expected for gestational age.
It is generally defined as:
amniotic fluid index (AFI) >25 cm
-
largest fluid pocket depth (maximal vertical pocket
(MVP))greater than 8>8 cm 6some centres, particularly in Australia, New Zealand, and the United Kingdom, use a cut off of
10>10 cmref
overall amniotic fluid volume
larger than 1500>1500-2000 mL 3two diameter pocket (TDP) >50 cm 2
Epidemiology
ItPolyhydramnios can occur in approximately 1-1.5% of pregnanciesref.
Associations
fetal macrosomia: independent of maternal diabetes 2,in the idiopathic form
maternal overhydration ref
Polyhydramnios is associated with poor outcomes if present in combination with intrauterine growth restriction (IUGR); usually seen in aneuploidies 18,13, and 21ref.
Clinical presentation
The patient may clinically present as a large for dates uterus.
Pathology
Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders.
It is usually detected after 20 weeks (often 3rd trimester).
Aetiology
The potential causes of polyhydramnios are variable including:
-
idiopathic: 60-65%
this is a diagnosis of exclusion despite accounting for a majority of cases, also termed idiopathic polyhydramnios
-
maternal: 25-30%
diabetes: commonly gestational diabetes
-
fetal: 10-20%
CNS lesions (e.g. neural tube defects): fetal CNS abnormalities tend to be the commonest out of all fetal causative associations 3
-
proximal gastrointestinal obstruction
-
gastrointestinal atresia(s)
fetal intestinal volvulus, e.g. from an intestinal malrotation
-
-
fetal cervicothoracic abnormalities
-
fetal cervical masses
-
thoracic masses
-
-
fetal cardiovascular anomalies
sustained fetal tachycardia (e.g. supraventricular tachycardia (SVT), atrial flutter, ventricular tachycardia) 12
-
twin pregnancy-related complications
twin-twin transfusion: occurs in the recipient
hydrops fetalis: immune and non-immune
-
fetal skeletal abnormalities
reduced fetal movement
Classification
This classification is general consensus based on common practices at the time of writing (July 2016) but this varies according to countries and gynaecologist association guidelines.
Some classify the severity of polyhydramnios as
mild: a single deepest pocket at 8-11 cm or amniotic fluid index (AFI) 25-30
moderate: a single deepest pocket at 12-15 cm or AFI 30.1-35
severe: single deepest pocket >16 cm or AFI >35
Treatment and prognosis
The prognosis is variable dependent on associated conditions. Usually minimal or no intervention is required for idiopathic mild uncomplicated cases. Options include:
improved maternal diabetes control
caesarian section if there is profound macrosomia
therapeutic amniocentesis/amnioreduction
-
indomethacinindometacin 9,10
Complications
The risk of the following obstetric complications is increased when polyhydramnios is present due to over-expansion of the uterus 13:
maternal dyspnoea
premature membrane rupture
postpartum haemorrhage: due to reduced uterine myometrial tone
See also
- +<li><p><a href="/articles/amniotic-fluid-index">amniotic fluid index (AFI)</a> >25 cm</p></li>
-<a href="/articles/amniotic-fluid-index">amniotic fluid index (AFI)</a> >25 cm</li>-<li>largest fluid pocket depth (<a href="/articles/maximal-vertical-pocket-mvp">maximal vertical pocket (MVP)</a>) greater than 8 cm <sup>6</sup><ul><li>-<sup></sup>some centres, particularly in Australia, New Zealand, and the United Kingdom, use a cut off of 10 cm</li></ul>-</li>-<li>overall <a href="/articles/amniotic-fluid-volume-1">amniotic fluid volume</a> larger than 1500-2000 mL <sup>3</sup>- +<p>largest fluid pocket depth (<a href="/articles/maximal-vertical-pocket-mvp">maximal vertical pocket</a>) >8 cm <sup>6</sup></p>
- +<ul><li><p><sup></sup>some centres, particularly in Australia, New Zealand, and the United Kingdom, use a cut off of >10 cm <sup>ref</sup></p></li></ul>
- +<li><p>overall <a href="/articles/amniotic-fluid-volume-1">amniotic fluid volume</a> >1500-2000 mL <sup>3</sup></p></li>
- +<li><p><a href="/articles/two-diameter-pocket">two diameter pocket</a> (TDP) >50 cm <sup>2</sup></p></li>
- +</ul><h4>Epidemiology</h4><p>Polyhydramnios can occur in 1-1.5% of pregnancies <sup>ref</sup>.</p><h5>Associations</h5><ul>
- +<li><p><a href="/articles/fetal-macrosomia">fetal macrosomia</a>: independent of maternal diabetes <sup>2</sup>,<sup> </sup>in the idiopathic form</p></li>
- +<li><p><a href="/articles/mesoblastic-nephroma">mesoblastic nephroma</a> <sup>ref</sup></p></li>
- +<li><p><a href="/articles/pena-shokeir-syndrome-2">Pena Shokeir syndrome</a> <sup>ref</sup></p></li>
- +<li><p>maternal overhydration <sup>ref</sup></p></li>
- +</ul><p>Polyhydramnios is associated with poor outcomes if present in combination with <a href="/articles/intrauterine-growth-restriction">intrauterine growth restriction (IUGR)</a>; usually seen in aneuploidies 18,13, and 21 <sup>ref</sup>.</p><h4>Clinical presentation</h4><p>The patient may clinically present as a <a href="/articles/large-for-dates-uterus">large for dates uterus</a>. </p><h4>Pathology</h4><p>Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders. </p><p>It is usually detected after 20 weeks (often 3<sup>rd</sup> trimester).</p><h5>Aetiology</h5><p>The potential causes of polyhydramnios are variable including:</p><ul>
-<a href="/articles/two-diameter-pocket">two diameter pocket</a> (TDP) >50 cm <sup>2</sup>- +<p><strong>idiopathic</strong>: 60-65%</p>
- +<ul><li><p>this is a diagnosis of exclusion despite accounting for a majority of cases, also termed <a href="/articles/idiopathic-polyhydramnios">idiopathic polyhydramnios</a></p></li></ul>
-</ul><h4>Epidemiology</h4><p>It can occur in approximately 1-1.5% of pregnancies.</p><h5>Associations</h5><ul>-<a href="/articles/fetal-macrosomia">fetal macrosomia</a>: independent of maternal diabetes <sup>2</sup>,<sup> </sup>in the idiopathic form</li>-<li><a href="/articles/mesoblastic-nephroma">mesoblastic nephroma</a></li>-<li><a href="/articles/pena-shokeir-syndrome-2">Pena Shokeir syndrome</a></li>-<li>maternal overhydration <sup>ref</sup>- +<p><strong>maternal</strong>: 25-30%</p>
- +<ul>
- +<li><p>diabetes: commonly <a href="/articles/gestational-diabetes">gestational diabetes</a></p></li>
- +<li><p><a href="/articles/maternal-congestive-heart-failure">maternal congestive heart failure</a> <sup>8</sup></p></li>
- +</ul>
-</ul><p>Polyhydramnios is associated with poor outcomes if present in combination with <a href="/articles/intrauterine-growth-restriction">intrauterine growth restriction (IUGR)</a>; usually seen in aneuploidies 18,13, and 21.</p><h4>Clinical presentation</h4><p>The patient may clinically present as a <a href="/articles/large-for-dates-uterus">large for dates uterus</a>. </p><h4>Pathology</h4><p>Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders. </p><p>It is usually detected after 20 weeks (often 3<sup>rd</sup> trimester).</p><h5>Aetiology</h5><p>The potential causes of polyhydramnios are variable including:</p><ul>-<strong>idiopathic: 60-65%</strong><ul><li>this is a diagnosis of exclusion despite accounting for a majority of cases, also termed <a href="/articles/idiopathic-polyhydramnios">idiopathic polyhydramnios</a>-</li></ul>-</li>- +<p><strong>fetal</strong>: 10-20%</p>
- +<ul>
- +<li><p>CNS lesions (e.g. <a href="/articles/neural-tube-defects">neural tube defects</a>): fetal CNS abnormalities tend to be the commonest out of all fetal causative associations <sup>3</sup></p></li>
-<strong>maternal: 25-30%</strong><ul>-<li>diabetes: commonly <a href="/articles/gestational-diabetes">gestational diabetes</a>-</li>- +<p>proximal gastrointestinal obstruction</p>
- +<ul>
-<a href="/articles/maternal-congestive-heart-failure">maternal congestive heart failure</a> <sup>8</sup>-</li>- +<p>gastrointestinal atresia(s) </p>
- +<ul>
- +<li><p><a href="/articles/oesophageal-atresia">oesophageal atresia</a></p></li>
- +<li><p><a href="/articles/duodenal-atresia">duodenal atresia</a> </p></li>
- +<li><p><a href="/articles/jejunal-atresia">jejunoileal atresia</a></p></li>
-<strong>fetal: 10-20%</strong><ul>-<li>CNS lesions (e.g. <a href="/articles/neural-tube-defects">neural tube defects</a>): fetal CNS abnormalities tend to be the commonest out of all fetal causative associations <sup>3</sup>-</li>-<li>proximal gastrointestinal obstruction<ul>-<li>gastrointestinal atresia(s) <ul>-<li><a href="/articles/oesophageal-atresia">oesophageal atresia</a></li>-<li>-<a href="/articles/duodenal-atresia">duodenal atresia</a> </li>-<li><a href="/articles/jejunal-atresia">jejunoileal atresia</a></li>- +<p><a href="/articles/fetal-anterior-abdominal-wall-defects">abdominal wall defects</a></p>
- +<ul>
- +<li><p><a href="/articles/gastroschisis">gastroschisis</a></p></li>
- +<li><p><a href="/articles/omphalocele-1">omphalocele</a></p></li>
-<li>-<a href="/articles/fetal-anterior-abdominal-wall-defects">abdominal wall defects</a><ul>-<li><a href="/articles/gastroschisis">gastroschisis</a></li>-<li><a href="/articles/omphalocele-1">omphalocele</a></li>- +<li><p><a href="/articles/fetal-intestinal-volvulus">fetal intestinal volvulus</a>, e.g. from an <a href="/articles/intestinal-malrotation">intestinal malrotation</a></p></li>
-<a href="/articles/fetal-intestinal-volvulus">fetal intestinal volvulus</a>, e.g. from an <a href="/articles/intestinal-malrotation">intestinal malrotation</a>-</li>-</ul>-</li>-<li>fetal cervicothoracic abnormalities <ul>-<li>fetal cervical masses<ul>- +<p>fetal cervicothoracic abnormalities </p>
- +<ul>
-<a href="/articles/congenital-cervical-teratoma">congenital cervical teratoma</a>/<a href="/articles/epignathus">epignathus</a>-</li>-<li>large <a href="/articles/fetal-goitre">fetal goitre</a>-</li>- +<p>fetal cervical masses</p>
- +<ul>
- +<li><p><a href="/articles/congenital-cervical-teratoma">congenital cervical teratoma</a>/<a href="/articles/epignathus">epignathus</a></p></li>
- +<li><p>large <a href="/articles/fetal-goitre">fetal goitre</a></p></li>
-<li>thoracic masses<ul>-<li><a href="/articles/congenital-cystic-adenomatoid-malformation">congenital pulmonary airways malformation (CPAM)</a></li>-<li>-<a href="/articles/congenital-high-airway-obstruction-syndrome">congenital high airways obstruction syndrome</a> <a href="/articles/chaos">(CHAOS)</a>-</li>-<a href="/articles/congenital-diaphragmatic-hernia-1">congenital diaphragmatic herniation</a> </li>- +<p>thoracic masses</p>
- +<ul>
- +<li><p><a href="/articles/congenital-cystic-adenomatoid-malformation">congenital pulmonary airways malformation (CPAM)</a></p></li>
- +<li><p><a href="/articles/congenital-high-airway-obstruction-syndrome">congenital high airways obstruction syndrome</a> <a href="/articles/chaos">(CHAOS)</a></p></li>
- +<li><p><a href="/articles/congenital-diaphragmatic-hernia-1">congenital diaphragmatic herniation</a> </p></li>
-<li>fetal cardiovascular anomalies<ul><li>sustained fetal tachycardia (e.g. <a href="/articles/fetal-supraventricular-tachycardia">supraventricular tachycardia (SVT)</a>, <a href="/articles/fetal-atrial-flutter">atrial flutter</a>, <a href="/articles/fetal-ventricular-tachycardia">ventricular tachycardia</a>) <sup>12</sup>-</li></ul>- +<li>
- +<p>fetal cardiovascular anomalies</p>
- +<ul><li><p>sustained fetal tachycardia (e.g. <a href="/articles/fetal-supraventricular-tachycardia">supraventricular tachycardia (SVT)</a>, <a href="/articles/fetal-atrial-flutter">atrial flutter</a>, <a href="/articles/fetal-ventricular-tachycardia">ventricular tachycardia</a>) <sup>12</sup></p></li></ul>
-<li>twin pregnancy-related complications<ul><li>-<a href="/articles/twin-to-twin-transfusion-syndrome-1">twin-twin transfusion</a>: occurs in the recipient</li></ul>- +<li>
- +<p>twin pregnancy-related complications</p>
- +<ul><li><p><a href="/articles/twin-to-twin-transfusion-syndrome-1">twin-twin transfusion</a>: occurs in the recipient</p></li></ul>
- +<li><p><a href="/articles/hydrops-fetalis">hydrops fetalis</a>: immune and non-immune</p></li>
-<a href="/articles/hydrops-fetalis">hydrops fetalis</a>: immune and non-immune</li>-<li>fetal skeletal abnormalities<ul><li>reduced fetal movement</li></ul>- +<p>fetal skeletal abnormalities</p>
- +<ul><li><p>reduced fetal movement</p></li></ul>
-<li>mild: a single deepest pocket at 8-11 cm or amniotic fluid index (AFI) 25-30</li>-<li>moderate: a single deepest pocket at 12-15 cm or AFI 30.1-35</li>-<li>severe: single deepest pocket >16 cm or AFI >35</li>- +<li><p>mild: a single deepest pocket at 8-11 cm or amniotic fluid index (AFI) 25-30</p></li>
- +<li><p>moderate: a single deepest pocket at 12-15 cm or AFI 30.1-35</p></li>
- +<li><p>severe: single deepest pocket >16 cm or AFI >35</p></li>
-<li>improved maternal diabetes control</li>-<li>caesarian section if there is profound macrosomia</li>-<li>-<a href="/articles/therapeutic-amniocentesis">therapeutic </a>amniocentesis/amnioreduction</li>-<li>indomethacin <sup>9,10</sup>-</li>- +<li><p>improved maternal diabetes control</p></li>
- +<li><p>caesarian section if there is profound macrosomia</p></li>
- +<li><p><a href="/articles/therapeutic-amniocentesis">therapeutic </a>amniocentesis/amnioreduction</p></li>
- +<li><p>indometacin <sup>9,10</sup></p></li>
-<li>maternal dyspnoea</li>-<li>premature membrane rupture</li>-<li><a href="/articles/pre-term-labour">preterm labour</a></li>-<li><a href="/articles/variation-in-fetal-presentation">abnormal fetal presentation</a></li>-<li><a href="/articles/umbilical-cord-prolapse">umbilical cord prolapse</a></li>-<li>-<a href="/articles/postpartum-haemorrhage">postpartum haemorrhage</a>: due to reduced uterine myometrial tone</li>-</ul><h4>See also</h4><ul><li><a href="/articles/oligohydramnios-1">oligohydramnios</a></li></ul>- +<li><p>maternal dyspnoea</p></li>
- +<li><p>premature membrane rupture</p></li>
- +<li><p><a href="/articles/pre-term-labour">preterm labour</a></p></li>
- +<li><p><a href="/articles/variation-in-fetal-presentation">abnormal fetal presentation</a></p></li>
- +<li><p><a href="/articles/umbilical-cord-prolapse">umbilical cord prolapse</a></p></li>
- +<li><p><a href="/articles/postpartum-haemorrhage">postpartum haemorrhage</a>: due to reduced uterine myometrial tone</p></li>
- +</ul><h4>See also</h4><ul><li><p><a href="/articles/oligohydramnios-1">oligohydramnios</a></p></li></ul>