Amniotic fluid is the term that describes the fluid surrounding the uterus. Amniotic fluid is produced through fetal urination. A sufficient amount of fluid must surround the fetus for proper protection and growth. The amniotic fluid helps the lungs to properly develop, and permits movement within the womb, allowing for good bone growth. The amniotic fluid contains many maternal and fetal nutrients such as water and electrolytes.
Why are Amniotic Fluid Levels Tested?
Conditions such as polyhydramnios (an excessive amount of fluid in the amniotic sac), and oligohydramnios (a deficiency of fluid in the amniotic sac), can occur during pregnancy. With either of these conditions, the health care provider will carefully monitor the pregnancy and condition of the fetus.
Oligohydramnios sometimes occurs with late pregnancies or ruptured membranes. This condition carries the risk of umbilical cord constriction, which can occur if there is insufficient fluid surrounding the baby. In rare cases, the condition indicates problems with the baby’s kidneys or urinary tract, or slow fetal development.
When polyhydramnios occurs, the growth of the fetus may also be affected. Too much amniotic fluid may create a greater risk of an umbilical cord prolapse (when the cord falls through the cervical opening ahead of the fetus), requiring a C-section.
How is Amniotic Fluid Tested?
Amniotic fluid index (AFI) is an estimate of the amount of amniotic fluid; it is a score given to the quantity of fluid measured on a pregnant uterus, and calculated by an ultrasound. An amniocentesis can also test the amniotic fluid and can provide useful information about the health and development of the fetus.