Neonatal adrenal insufficiency: diagnosis and stress dosing

Neonatal adrenal insufficiency is an uncommon but potentially life-threatening endocrine disorder. In the first weeks of life, inadequate cortisol production can present as hypoglycemia, hypotension, electrolyte disturbance, poor feeding, lethargy, prolonged jaundice, or unexplained clinical deterioration. Because these signs overlap with sepsis, hypoxic injury, and other neonatal conditions, recognition often depends on combining clinical patterns with targeted laboratory testing.

The condition may arise from primary adrenal disease, impaired hypothalamic-pituitary-adrenal signaling, congenital adrenal hyperplasia, adrenal hemorrhage, genetic disorders, or temporary suppression after exposure to maternal or postnatal glucocorticoids. Prematurity and critical illness further complicate interpretation because cortisol concentrations and stress responses change with gestational and postnatal age.

Treatment should never be delayed in a seriously ill infant when adrenal crisis is plausible. Blood samples can be collected before hydrocortisone when this will not postpone treatment, but stabilization of airway, circulation, glucose, and electrolytes remains the immediate priority. Neonatal endocrinology input is important for confirming the diagnosis and adjusting therapy as the infant recovers.

Recognizing the clinical pattern

A newborn with cortisol deficiency may have nonspecific symptoms at first. Weakness, vomiting, feeding intolerance, temperature instability, prolonged capillary refill, and reduced responsiveness can resemble infection. Recurrent or severe hypoglycemia, especially when it occurs without appropriate ketones, should increase concern for an inadequate counter-regulatory response.

Primary adrenal insufficiency may produce hyperkalemia, hyponatremia, dehydration, and hypotension because aldosterone production can also be impaired. In central adrenal insufficiency, potassium is often normal because mineralocorticoid secretion is mainly regulated by the renin-angiotensin system. Hypoglycemia may be the dominant feature, while genital ambiguity or atypical genitalia may point toward congenital adrenal hyperplasia.

Risk assessment should include gestational age, birth stress, placental complications, medication exposure, and family history. Placental dysfunction and severe maternal hypertension can affect neonatal adaptation; background reading on preeclampsia mechanisms can help place these perinatal risks in context without treating them as diagnostic proof of adrenal disease.

Establishing the diagnosis safely

The most useful initial sample is a serum cortisol obtained during illness, ideally before glucocorticoid administration. Its interpretation must account for timing, gestational age, binding proteins, assay method, and the infant’s degree of physiologic stress. A “normal” cortisol in a calm, stable infant does not answer whether the adrenal glands can respond adequately during shock or hypoglycemia.

A paired plasma ACTH concentration helps distinguish primary from central disease. High ACTH with low cortisol suggests primary adrenal failure, whereas low or inappropriately normal ACTH supports central suppression or pituitary-hypothalamic disease. Additional tests may include electrolytes, glucose, bicarbonate, renin, aldosterone, 17-hydroxyprogesterone, androstenedione, dehydroepiandrosterone sulfate, and urinary steroid profiling when congenital adrenal hyperplasia or a steroidogenesis defect is suspected.

Cosyntropin stimulation testing can be useful after initial stabilization, but neonatal protocols are not fully uniform. The dose, sampling intervals, assay platform, and cortisol threshold differ between centers. A suboptimal response supports impaired adrenal reserve, yet a single test should be interpreted with the clinical picture and endocrine consultation. Recent glucocorticoid exposure can suppress results or interfere with interpretation, particularly when dexamethasone, hydrocortisone, or topical steroids have been used.

Distinguishing causes in the newborn period

Primary adrenal insufficiency includes congenital adrenal hyperplasia, adrenal hypoplasia, familial glucocorticoid deficiency, and destructive processes such as bilateral adrenal hemorrhage. Congenital adrenal hyperplasia caused by 21-hydroxylase deficiency is especially important because salt-wasting crisis can develop after the first days of life. Newborn screening is valuable, but a negative or pending screen must not override clinical evidence in an unstable infant.

Central adrenal insufficiency may follow pituitary or hypothalamic abnormalities, midline defects, genetic syndromes, or prolonged suppression from exogenous glucocorticoids. Infants with multiple pituitary hormone deficiencies may also show cholestasis, micropenis, prolonged hypoglycemia, or poor growth. Brain imaging and assessment of other pituitary axes are guided by the clinical findings rather than performed automatically in every infant with a low cortisol.

Maternal conditions and medications may alter neonatal endocrine function. Babies exposed to sustained maternal corticosteroid therapy can have transient hypothalamic-pituitary-adrenal suppression, while placental transfer of some drugs may affect glucose regulation or blood pressure. Maternal autoimmune disease can also shape neonatal evaluation; a practical resource on autoimmune disease in pregnancy provides useful context for reviewing maternal history, medications, and antibody-related risks.

Managing suspected adrenal crisis

When adrenal crisis is suspected, treatment includes stress-dose hydrocortisone, glucose correction, careful isotonic fluid resuscitation, and management of hyperkalemia or acidosis. A commonly used emergency approach is hydrocortisone 25 mg/m² intravenously or intramuscularly as an initial dose, followed by approximately 50–100 mg/m² per day divided every six hours. Local neonatal protocols may use weight-based alternatives, so the dosing plan should be confirmed urgently with a neonatologist or pediatric endocrinologist.

Hydrocortisone is generally preferred because it provides glucocorticoid activity and, at stress doses, useful mineralocorticoid activity. If adrenal crisis is strongly suspected, therapy should not wait for an ACTH stimulation test or the return of send-out steroid results. Dextrose should be given for clinically significant hypoglycemia, with repeat glucose measurements because recurrent low values may continue until cortisol activity is restored.

Fluids require restraint and close monitoring. Rapid correction of dehydration may be necessary in shock, but premature infants and critically ill neonates are vulnerable to fluid overload, sodium shifts, and cardiac dysfunction. Blood pressure, urine output, glucose, sodium, potassium, bicarbonate, and acid-base status should be followed frequently. If sepsis is also possible, antimicrobial treatment should proceed in parallel rather than being replaced by endocrine treatment.

Planning replacement and stress coverage

Once the infant is stable, the regimen can transition from crisis treatment to physiologic replacement. Hydrocortisone is often prescribed in divided doses, with the total daily amount individualized according to age, diagnosis, growth, clinical response, and endocrine testing. Infants with confirmed primary adrenal insufficiency may also need fludrocortisone and sodium supplementation, while those with isolated central cortisol deficiency usually do not require mineralocorticoid replacement.

Families need a written sick-day plan before discharge. It should explain when to increase oral hydrocortisone for fever, vomiting, poor intake, injury, or significant infection; when oral medication is unsafe; and how to give emergency intramuscular hydrocortisone. Caregivers should receive hands-on training, an emergency injection kit, medical identification guidance, and clear instructions for contacting emergency services.

Stress coverage is also relevant during surgery, invasive procedures, prolonged fasting, and severe respiratory or gastrointestinal illness. The exact dose depends on the procedure and the infant’s baseline replacement schedule. Vomiting, persistent hypoglycemia, collapse, or inability to absorb oral medication should be treated as reasons for parenteral hydrocortisone and urgent medical assessment rather than repeated oral doses.

Monitoring recovery and long-term safety

Follow-up aims to confirm the cause, avoid both undertreatment and glucocorticoid excess, and determine whether adrenal function recovers. Serial clinical review includes weight gain, feeding, blood pressure, hydration, growth, pigmentation, electrolyte balance, and the frequency of intercurrent illness. Laboratory reassessment may involve morning cortisol, ACTH, renin, electrolytes, and stimulation testing after medication has been adjusted under specialist supervision.

Transient suppression can improve over weeks or months, but recovery is unpredictable. Infants with genetic primary adrenal disorders generally require long-term care, whereas those with medication-related suppression may eventually taper replacement. Hydrocortisone should not be stopped abruptly when ongoing adrenal suppression remains possible; discontinuation should follow a documented endocrine plan.

Neonatal teams benefit from standardized pathways that connect delivery-room stabilization, laboratory sampling, treatment thresholds, discharge education, and outpatient review. The former congress site, FAOPS 2020 resources, reflects the wider perinatal medicine community’s emphasis on coordinated neonatal and maternal care, even though the scheduled Tokyo meeting itself was canceled during the COVID-19 pandemic.

Practical safeguards for neonatal teams

A reliable approach combines rapid treatment with disciplined documentation. Every suspected case should have a clear timeline of symptoms, medication exposures, blood samples, hydrocortisone doses, glucose interventions, and electrolyte changes. This record helps specialists distinguish true adrenal failure from transient illness-related cortisol abnormalities.

Useful bedside safeguards include:

• Draw cortisol, ACTH, electrolytes, glucose, and relevant steroid tests before hydrocortisone when this causes no treatment delay.
• Treat hypoglycemia, shock, and suspected adrenal crisis immediately rather than waiting for confirmatory endocrine results.
• Review maternal steroids, neonatal steroid exposure, prematurity, placental complications, and family history.
• Involve pediatric endocrinology when the diagnosis is uncertain, mineralocorticoid deficiency is suspected, or stimulation testing is being planned.
• Discharge only after caregivers understand sick-day rules, emergency injection technique, and follow-up arrangements.

Early recognition is especially important because adrenal crisis can progress quickly while appearing indistinguishable from sepsis or metabolic disease. A structured diagnostic strategy, prompt stress dosing, and careful follow-up give vulnerable newborns the best chance of safe stabilization and accurate long-term care. Perinatal clinicians can use these principles to review local protocols, strengthen emergency education, and ensure that every infant at risk has a documented plan before leaving hospital.