From the Guidelines
Polyhydramnios is most commonly caused by maternal diabetes mellitus, fetal anomalies, multiple gestations, and fetal anemia, with approximately 60% of cases being idiopathic. The causes of polyhydramnios can be broadly categorized into:
- Maternal factors, such as diabetes mellitus, which can lead to fetal hyperglycemia and subsequent polyuria, increasing amniotic fluid production 1
- Fetal factors, including gastrointestinal and central nervous system anomalies, which can impair the fetus's ability to swallow and absorb amniotic fluid normally 1
- Multiple gestations, particularly twin-twin transfusion syndrome, which can lead to an imbalance in amniotic fluid production and absorption 1
- Fetal anemia, which can increase amniotic fluid production due to increased cardiac output and subsequent increased urine production 1 It is essential to identify the underlying cause of polyhydramnios, as management and outcomes can vary significantly depending on the etiology. In cases where no specific cause is identified, the condition is classified as idiopathic polyhydramnios. The pathophysiology of polyhydramnios generally involves either increased production of amniotic fluid or decreased fetal consumption, highlighting the importance of understanding the underlying mechanisms to guide management decisions.
From the Research
Common Causes of Polyhydramnios
- Fetal anatomical and genetic abnormalities 2, 3, 4, 5, 6
- Gestational diabetes mellitus 2, 3, 4, 5, 6
- Fetal viral infections 2, 3, 5, 6
- Congenital infection and alloimmunization 4
- Idiopathic reasons 4, 5, 6
- Multiple gestations 6
- Chromosomal disorders 6
- Isoimmunologic disease 6