Oligohydramnios

Etiology:
— Fetal causes: 60% of amniotic fluid is from fetal urine so if fetal kidneys produce little urine (renal agenesis, autosomal recessive polycystic kidney disease, renal obstruction due to posterior urethral valves, Prune belly syndrome, bilateral multicystic dysplastic kidney) this leads to oligohydramnios which leads to fetal compression
— Maternal causes: Chronic leak of amniotic fluid or premature rupture of membranes or placental insufficiency
Imaging:
— Bell-shaped chest due to pulmonary hypoplasia
— Deformities of long bones
— Skull molding
DDX:
Complications: Respiratory distress
Treatment:
Clinical: Potter’s facies – flattened face and low set ears due to fetal compression

Radiology Cases of Oligohydramnios

CXR of pulmonary hypoplasia due to oligohydramnios — CXR AP shows bilateral poorly developed and poorly expanded lungs.

Radiology Cases of Oligohydramnios Due to Autosomal Recessive Polycystic Kidney Disease Resulting in Pulmonary Hypoplasia

CXR and US of autosomal recessive polycystic kidney disease causing oligohydramnios and pulmonary hypoplasia — CXR AP (above) shows a small bell-shaped thorax with poorly expanded lungs despite being on a ventilator. Transverse US of the left kidney (below left) and right kidney (below right) shows the kidneys bilaterally to be enlarged and to be composed of innumerable microcysts giving the kidneys overall an echogenic appearance.

Radiology Cases of Oligohydramnios Due to Multicystic Dysplastic Kidney Resulting in Pulmonary Hypoplasia

CXR of patient with oligohydramnios — CXR AP shows a bell-shaped chest with extremely low lung volumes.

Radiology Cases of Oligohydramnios Due to Urethral Atresia

AXR of urethral atresia — Postmortem CXR and AXR shows an extremely distended abdomen due to bilateral abdominal masses resulting in a small thorax. An umbilical catheter fragment is also present.

US of urethral atresia resulting in cystic renal dysplasia, urine ascites and oligohydramnios — Sagittal US of the left kidney (above left) shows it to be small, echogenic, and to contain multiple cysts. Sagittal US of the right kidney (above right) shows it to have a similiar appearance. There is also a large amount of anechoic fluid around the right kidney which represents urine ascites. Transverse US of the bladder (below left) shows it to be thick walled. CXR AP (below right) shows a small bell-shaped chest with bilateral chest tubes present that were treating the bilateral pneumothoraces that were present at birth.

Clinical Cases of Oligohydramnios

Clinical image of Potter syndrome due to pulmonary hypoplasia — Clinical image shows a flattened nose, recessed chin, prominent epicanthial folds and low set of abnormal ears.

Clinical Cases of Oligohydramnios Due to Urethral Atresia

Clinical image of Potter's facies due to urethral atresia — Post-mortem gross pathological image shows Potter’s facies – a flattened face and low set ears – and a small thorax with pulmonary hypoplasia and large abdomen.

Gross Pathology of Oligohydramnios

Gross Pathology of Oligohydramnios Due To Urethral Atresia

Gross pathology image of cystic renal dysplasia and a trabeculated bladder due to urethral atresia — Post-mortem gross pathological image shows bilaterally enlarged kidneys containing multiple large cysts and a trabeculated bladder inferior to the right kidney.

Gross pathology image of cystic renal dysplasia and a trabeculated bladder due to urethral atresia — Post-mortem gross pathological image shows enlarged kidneys containing multiple large cysts bilaterally, left hydroureter (which was also present on the right) and a thick walled and trabeculated bladder.

Gross pathology image of cystic renal dysplasia due to urethral atresia — Gross pathological sectioned image shows an enlarged kidney which contains multiple large cysts.