What Is Anhydramnios?

Anhydramnios is a condition, occurring in pregnancy, in which there is no amniotic fluid around the fetus. The condition can cause a number of problems, including respiratory failure once the infant is born. With modern medical intervention, anhydramnios is not always deadly, though it does require a quick response by the infant’s medical team. It can be caused by a tear in the lining of the placenta or by a problem with the developing fetus’s kidneys or urinary tract. It is related to oligohydramnios, which happens when there is not enough amniotic fluid around the fetus.

Amniotic fluid is important to the proper development of a fetus. This fluid is made up mostly of the fetus’s own urine, which it begins producing in the first trimester. If anhydramnios occurs, there will not be any fluid around the fetus, and a number of potentially serious problems can develop.

One of the most severe complications of anhydramnios is that the lungs will not develop properly, which will cause respiratory distress at birth. While it is in the uterus, the fetus goes through the motions of breathing, which helps the muscles surrounding the lungs to develop. An enzyme known as proline is also found in amniotic fluid, which the alveoli need in order to mature. The lack of amniotic fluid can also cause a set of fetal malformations in the feet and head known as Potter’s sequence or syndrome.

If the anhydramnios is the result of a tear in the lining of the placenta, there is a chance that the infant can survive past birth. The infant will require assistance with breathing for a time. In most cases, however, the complete lack of amniotic fluid will leave the infant’s lungs severely underdeveloped.

Anhydramnios that is the result of the poor development of the fetus’s kidneys or urinary tract may be more difficult for the infant to recover from. The complete lack of amniotic fluid indicates a severe problem with the organs of the urinary system. A fetus that develops without kidneys, ureters or a bladder will likely die just after birth. If, however, these organs are present and underdeveloped, it may be possible to keep the infant alive until it is old enough to undergo restorative surgery and a possible kidney transplant, but this depends on whether or not the lungs can function.