Potter's sequence describes the typical physical appearance caused by pressure in utero due to oligohydramnios. The olighydramnios can occur due to a range of variety of reasons. When it is a result of bilateral renal agenesis, it is called Potter Syndrome.

It is called Potter sequence to reflect that the phenotype results due to a sequence of events resulting form the oligohydramnios:

• Renal tract complications result in reduced amniotic fluid production
  • The lack of amniotic fluid results in foetal compression causing the characteristic facial and limb features
  • The lack of amniotic fluid also affects lung development, causing pulmonary hypoplasia

P - pulmonary hypoplasia

O - Oligohydramnios

T - twisted faces

T - twisted skin

E - extremity deformities

R - Renal agenesis

PC

Facial signs include:

• Flattened 'parrot-beaked' nose
• Recessed chin
• Downward epicanthal folds
• Low-set, cartilage-deficient ears (known as 'Potter's ears')

Pulmonary hypoplasia can result in the baby having respiratory distress at birth.