2. Clinical Embryology Flashcards
What do the terms in POTTER syndrome stand for?
Pulmonary hypoplasia Oligohydramnios Twisted face Twisted skin Extremity defects Renal failure/agenesis
What is defined as oligohydramnios?
Less than 0.5l amniotic fluid
Give five causes of oligohydramnios.
- ARPKD
- Obstructive uropathy - ureteric atresia, posterior urethral valve
- Amniotic rupture
- Chronic placental insufficiency
- Bilateral renal agenesis
Why does POTTER syndrome affect males more than females?
More likely to have obstructive uropathies.
Describe five facial features of POTTER syndrome.
Flattened face, wide set eyes, epicanthal folds, retrognathia, low set ears.
Give two ways amniotic fluid supports pulmonary development.
- Fluid physically pushes open airways and stretches alveoli
- Contains amino acids which help form connective tissue and collagen e.g. Proline
How does oligohydramnios cause the facial, skin and limb defects seen in POTTER syndrome?
Less fluid - less protection from the muscular wall of the uterus which then causes compression of the foetus
How is POTTER syndrome diagnosed?
Via USS usually during second trimester
Which artery do the fused kidneys get stuck under?
Inferior mesenteric artery
Which renal cancers is horseshoe kidney most likely to be associated with?
Wilms tumour, carcinoid tumour
Which genetic disorders are associated with horseshoe kidney?
Turner syndrome, trisomy 13, 18, 21
Give three complications that can occur due to horseshoe kidney.
Infections, hydronephrosis, renal stones
What is the most common cause of bladder outlet obstruction in male infants?
Posterior urethral valves
What two features on prenatal USS can help diagnose posterior urethral valves?
Bilateral hydronephrosis and dilated or thick walled bladder
Why does having an extra ureter entering the bladder increase the risk of VUR?
Increased chance of incorrect angle of entry which prevent ureter being closed off properly when the bladder is full
