Potter sequence refers to a group of features that can result when there is too little amniotic fluid (oligohydramnios) surrounding a baby while in the uterus. This can cause distinct facial features (Potter facies), which may include a flattened nose, recessed chin, skin folds covering the corners of the eyes (epicanthal folds), and low-set abnormal ears. Having low amniotic fluid can also result in underdevelopment of the lungs (pulmonary hypoplasia). Other associated features may include eye malformations and heart defects.

There are various causes of Potter sequence including failure of the kidneys to develop (bilateral renal agenesis), polycystic kidney diseases, prune belly syndrome, rupture of membranes surrounding the baby, and other kidney abnormalities. The underlying cause of the sequence is often undetermined, but it may be genetic in some cases. The inheritance pattern depends on the specific genetic cause. Diagnosis is based on ultrasound findings or the presence of characteristic symptoms such as kidney malfunction and difficulty breathing. Treatment depends on the underlying cause of the sequence.

Babies with Potter sequence have a problem with the kidneys or urinary tract that is preventing them from producing the correct amount of urine. This causes there to be a low amount of amniotic fluid (oligohydramnios). When there is not enough amniotic fluid, the baby’s lungs also become underdeveloped (pulmonary hypoplasia). The low amount of amniotic fluid also causes the typical facial features seen in babies with Potter sequence (Potter facies) because there is not enough fluid to provide protection from the walls of the uterus.

The exact cause of the low levels of amniotic fluid in babies with Potter sequence may vary. Possible causes include failure of the kidneys to develop (bilateral renal agenesis), polycystic kidney diseases, and prune belly syndrome. Other causes may include urinary tract obstructions, exposures to harmful substances during pregnancy, or rupture of the membranes that surround the baby, causing amniotic fluid to leak. In some cases, the exact cause of Potter sequence may not be understood.

If Potter sequence is suspected, tests may be completed to attempt to determine the underlying cause of the sequence or to find out more information about the severity. These tests may include genetic testing, measuring urine output, imaging studies, and blood tests.

Babies with Potter sequence may require help in order to breathe when they are born. This may include resuscitation when the baby is born and ventilation to help maintain normal breathing. If there are problems with the baby’s kidneys, dialysis (removing toxins from the blood) may be recommended until other treatment becomes available. Some babies with Potter sequence may also require feeding tubes to make sure they are getting enough nutrition.

It is important for parents who have babies with Potter sequence to remember that treatment may not help all babies survive. If the underlying cause of Potter sequence is determined to have a poor long-term outlook, some parents decide not to perform extreme life-saving measures. If Potter sequence is diagnosed prenatally, the doctors and parents should work together to make a delivery plan. Personalized information should be provided depending on each situation so that the best decision can be made for the family.