Oligohydramnios is a condition that can develop during pregnancy. It occurs when not enough amniotic fluid, which surrounds the fetus, is produced. Oligohydramnios sequence is the pattern of abnormalities that results. Oligohydramnios sequence, or Potter’s syndrome, can cause severe abnormalities of the fetus.
Not all fetuses develop abnormalities because of low levels of amniotic fluid.
Whether oligohydramnios sequence occurs depends on the stage of pregnancy and how low amniotic fluid levels are.
Oligohydramnios occurs in about 4 percent of pregnancies. Not all cases involve a severe decrease in fluid. Oligohydramnios sequence occurs in about 1 in 4,000 births.
It is not always possible to determine what causes low levels of amniotic fluid.
Oligohydramnios can be caused by a continuous leaking of amniotic fluid. It can also occur when the fetus has kidney failure. After about four months of pregnancy, the kidneys of a normal fetus will produce the amniotic fluid. If the fetus has kidney abnormalities, the amount of amniotic fluid may be too low.
There appears to be a genetic reason for some causes of fetus kidney failure. Two genetic diseases that can cause oligohydramnios sequence are autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease.
A family history of certain renal diseases may increase a woman’s risk of developing oligohydramnios sequence during pregnancy.
Amniotic fluid serves a few different purposes for the fetus. The fluid helps lubricate the fetus’s body parts and prevents them from fusing. It also cushions the fetus and helps with lung development. Several fetal symptoms can occur when amniotic fluid is too low.
Limited amniotic fluid makes the ammonic cavity smaller than normal. This constricts the fetus, which interferes with normal development and growth. The symptoms of oligohydramnios sequence in a fetus can include facial abnormalities such as a broad nasal bridge, widely spaced eyes, and low set ears.
When oligohydramnios sequence is caused by fetal kidney failure, urine output after birth is low or absent. Limited amniotic fluid also interferes with normal lung development. If a baby survives through birth, he or she will likely have difficulty breathing (Penn Medicine).
A physician can diagnose oligohydramnios sequence with an ultrasound. An ultrasound can detect low levels of amniotic fluid and abnormal kidney development in the fetus.
Leaking amniotic fluid is another possible sign of oligohydramnios sequence. Leaking does not always occur.
After a baby is born, an X-ray of the lungs and kidneys can help a doctor check for abnormal development. This can help diagnose oligohydramnios sequence in a newborn.
There is currently no cure for oligohydramnios sequence. In many cases, the condition can cause a miscarriage. In other cases, the fetus is stillborn or dies shortly after birth. If a baby survives until birth, resuscitation may be needed.
The prognosis for oligohydramnios sequence is usually very poor. The condition is usually fatal.
According to the U.S. National Library of Medicine, there is currently no known prevention for oligohydramnios sequence (U.S. National Library of Medicine).