Oligohydramnios is too little fluid in the amniotic sac. The amniotic sac is the water bag inside the uterus that cushions and protects your baby. It also allows normal growth and development to occur. Normal amniotic fluid levels vary. The average volume during pregnancy is almost one liter at 36-37 weeks.

Low amniotic fluid can indicate a problem in the mother or the baby. It can also cause problems that vary depending on when in pregnancy oligohydramnios occurs.

Problems in the first half of pregnancy may include:

  • Higher risk of miscarriage
  • Compression of the baby, leading to birth defects
  • Lack of lung development

Problems in the second half of pregnancy may include:

  • Reduced growth of baby
  • Preterm birth
  • Fetal distress in labor, possibly leading to cesarean section

Fetus in Utero, Amniotic Fluid
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There are many known causes of oligohydramnios. However, sometimes a specific cause cannot be found. Conditions that can cause oligohydramnios include:

  • Birth defects
  • Problems with the fetus's urinary system
  • A problem with the placenta
  • Tear in the amniotic sac
  • Pregnancy continuing past the due date
  • Problems in the mother, such as dehydration, diabetes, or high blood pressure
  • Complication of certain medications