Amniotic fluid is protective liquid inside the amniotic sac (of a pregnant woman).

• Maternal plasma passes through fetal tissue to become watery-like fluid. Although originally water and electrolyte, there is later protein, carbohydrate, lipids, phospholipids, and urea, which aid growth of the fetus. When a woman's water breaks, the amnion ruptures, and the amniotic fluid is released.

• Amniotic fluid index (AFI) is an estimate of the amount of amniotic fluid, based on the centimeter measurement of an U/S of a pregnant uterus. It indicates fetal well-being. Scores for AFI include:
  • <6, which is considered oligohydramnios
  • 8-18, which is normal. AFI is approximately 14 from week 20-25, from when the amniotic fluid begins to reduce in preparation for birth
  • >20, which is considered polyhydramnios

• Vaginal discharge
• Pregnancy ultrasound (AFI is a component of a pregnancy U/S)