Low level of amniotic fluid during pregnancy; below the 5th centile for the gestational age

Aetiology

• Anything that reduces the production of urine, blocks output from the foetus, or a rupture of the membranes (allowing amniotic fluid to leak) can lead to oligohydramnios
• Main causes are:
  • Preterm prelabour rupture of membranes
  • Placental insufficiency
  • Non-functioning fetal kidneys
  • Obstructive uropathy
  • Genetic/chromosomal anomalies
  • Viral infections

Investigations

• Ultrasound: amniotic fluid index (AFI) or maximum pool depth (MPD)

Management

• Depends on underlying cause