Neonatal Adrenal Haemorrhage

Neonatal adrenal haemorrhage is bleeding into the adrenal gland in the newborn, which may be unilateral or bilateral and is usually asymptomatic. It presents as a flank mass, jaundice, anaemia or scrotal discolouration, or incidentally on ultrasound.

It is found in about 1.7 in 1000 neonates at ultrasound screening and more often at autopsy. About 70% are right sided because the right adrenal vein drains directly to the inferior vena cava. Bilateral disease occurs in about 5 to 10%.

Risk factors are birth trauma, macrosomia, breech or difficult delivery, perinatal asphyxia, sepsis, coagulopathy, thrombocytopenia, maternal diabetes and stress. Most cases resolve with no sequelae over weeks to months.

Pathophysiology.

The neonatal adrenal gland is large, with a relatively thick vascular foetal zone, and has a delicate vascular supply that drains through a single central vein. Venous congestion or stress related increase in ACTH and blood flow can cause haemorrhage.

Bleeding is usually contained. Bilateral destruction of cortex can cause adrenal insufficiency.

• Often asymptomatic, found incidentally on ultrasound.
• Flank or abdominal mass, jaundice (from absorption of blood), pallor and anaemia.
• Scrotal swelling with bluish discolouration (blood tracks through the inguinal canal), or abdominal distension.
• Bilateral haemorrhage: adrenal insufficiency with poor feeding, vomiting, hypotension, hypoglycaemia, hyponatraemia, hyperkalaemia and shock.

Red flags.

• Hypotension, hypoglycaemia, hyponatraemia or hyperkalaemia suggesting adrenal crisis.
• Falling haemoglobin, shock or haemoperitoneum.
• A mass that persists or grows, or elevated catecholamine metabolites, which suggests neuroblastoma.

• Abdominal ultrasound with Doppler: an initially echogenic mass that becomes cystic and then shrinks, may calcify, and has no internal blood flow. Compare with neuroblastoma, which is solid, vascular and often persistent.
• Serial ultrasound weekly at first and then at intervals until resolution, in about 4 to 6 weeks to several months.
• Urinary catecholamine metabolites (vanillylmandelic acid and homovanillic acid) to exclude neuroblastoma. MRI when the diagnosis is uncertain.
• Full blood count, coagulation, platelet count, bilirubin, and for bilateral disease or any symptoms: sodium, potassium, glucose, 17-hydroxyprogesterone, cortisol and ACTH, and a short corticotropin test when stable.

Differential diagnosis. Neuroblastoma, renal vein thrombosis, Wilms tumour, adrenal abscess, kidney lesions, congenital adrenal hyperplasia, and testicular torsion or tumour in cases with scrotal signs.

• Unilateral, uncomplicated haemorrhage: observation and supportive care. Monitor haemoglobin and transfuse red cells 10 to 15 mL/kg for significant anaemia. Give vitamin K 1 mg IM if not already given, and correct coagulopathy and thrombocytopenia.
• Treat hyperbilirubinaemia with phototherapy by the age specific and gestation specific chart.
• Bilateral haemorrhage or symptoms of adrenal insufficiency: take cortisol and ACTH samples, then give hydrocortisone 2 mg/kg IV as a bolus (or 50 to 100 mg/m2), followed by 50 to 100 mg/m2/day in 4 divided doses, with 0.9% sodium chloride 10 to 20 mL/kg for shock and 10% glucose 2 mL/kg for hypoglycaemia. Add fludrocortisone 0.05 to 0.2 mg daily for mineralocorticoid deficiency, and sodium supplements. Weaning is directed by cortisol testing.
• Surgery is rarely needed (for rupture or uncontrolled bleeding).
• Suspected neuroblastoma or persistent mass: oncology referral.

Monitoring. Ultrasound until the lesion resolves or calcifies, urinary catecholamines if the mass persists, haemoglobin, bilirubin, and in bilateral cases, electrolytes and adrenal function for months.

Referral and escalation. Refer to paediatric endocrinology for bilateral or symptomatic disease, to paediatric surgery or oncology for a persistent or growing mass, and urgently for shock.