Foetal adrenal glands are large in size; in the first weeks of life they are larger than the kidneys. In the second half of gestation the glands undergo a rapid involution and in a full-term neonate they are merely 1/3 of the normal kidney length. After birth their size continues to decrease swiftly with a simultaneous development of function (5).

The structure and the function of the adrenal medulla and cortex differ but the intra-adrenal glycocorticoid level may affect the conversion of norepinephrine into epinephrine. Glycocorticoids may exert their effect on the N-methyl-phenyl-ethanolamine enzyme level which is linked with the conversion. So far it has not been clearly stated how both adrenal glands affect each other, and diseases, particularly those of the adrenal medulla in foetal and neonatal life, are very rarely diagnosed (7).

The adrenal cortex secretes three main groups of hormones:

1. glycocorticoids - hydrocortisone is the most important of those and has the greatest effect on the metabolism of carbohydrates, proteins and fats;

2. mineralocorticoids - aldosterone and desoxycorticosterone affect water and mineral balance, mainly by promoting sodium retention and exchange of hydrogen ions for potassium in the distal renal canaliculi;

3. adrenal androgens - dehydroandrosterone, androstedion, and 11-B-hydroxyandrostendion in neonates are responsible for protein anabolism, and also for the type of pubic hair, mainly in girls at puberty.

The adrenal medulla secretes physiologically active catecholamines into the bloodstream, such as dopamine, noradrenaline and adrenaline, which have a potent effect on the circulatory system, the release of liver glucose and fatty acids - Catecholamine metabolites - vanillylmandelic acid (VAM), metaadrenaline and noradrenaline - are excreted into urine and may be determined for diagnostic reasons.

Anatomic and physiological abnormalities of the adrenal glands may affect only one of them, rarely both (only 10%) (7).

Haemorrhage into the adrenal glands resulting from a complicated labour, bleeding tendency or hypoxia, is a specific injury which may be associated with acute endocrine disorders which are life-threatening to the neonate (adrenal crisis).

Before the introduction of new imaging techniques such as ultrasonography (USG), computerised tomography (CT), and magnetic resonance (MRI), haemorrhage into the adrenal glands had been diagnosed very rarely, mainly at postmortem examination (3). In both old and new paediatric textbooks, haemorrhage into the adrenal glands in neonates as the primary cause of adrenal insufficiency is listed last, after congenital adrenal hyperplasia, immune and infectious disorders and neoplasia. In textbooks on neonatal endocrine disorders, hypotension and shock associated with haemorrhage into the adrenal glands, occurring in the perinatal period, are also dealt with marginally, although they are included among life-threatening causes in the neonate. Neither international nor Polish literature include reports which would present a more updated approach, despite the fact than an increasing number of abdominal and renal USG scans show evidence of haemorrhage into the adrenal glands and calcification varying in size and severity whose location is compatible with the adrenal glands.

Reported cases of calcification are associated mainly with one adrenal gland, and very rarely both. They are differentiated with calcification in the course of meconium and ileitis nauroblastoma, teratoma, and congenital Wolman´s syndrome. A small or merely one-sided haemorrhage into the adrenal glands generally does not lead to acute adrenal insufficiency. A large or moderate haemorrhage may be masked by other severe neonatal diseases: sepsis with shock, CNS injury, asphyxia, intestinal obstruction and/or atresia, pulmonary hypertension, severe anaemia, or circulatory insufficiency, because their clinical manifestations are not specific only for adrenal injury damage. In severely damaged adrenal glands there is a dramatic onset of hypovolaemic shock, hypotension, abnormal thermoregulation, carbohydrate metabolism and water and mineral imbalace, tachycardia, arrhythmia, and cyanosis. Anorexia and rapid weight loss are present. Hypoglycaemia is difficult to treat and may be accompanied by convulsions. Ion disturbances include decreased serum concentration of sodium, chlorine, occasionally calcium, and an increased concetration of potassium. Similar clinical manifestations and ion disturbances may occur in CNS injury in the neonate, mainly that of the hypthalamus and/or pituitary gland, these being the organs centrally controlling adrenal homeostasis. Diagnosis to confirm acute adrenal insufficiency is difficult, particularly when the symptoms in the neonate are life-threatening and are an indication for intensive therapeutic measures including administration of adrenal preparations.

Therefore, the neonate must undergo planned immediate investigations in order to detect possible haemorrhage into the internal organs, congenital defects and infections. The urgently required treatment should not delay differential diagnoses (2).

Additional difficulties in assessing hormonal disturbances in the neonate arise from unsTable concentrations of particular adrenal hormones for at least the first 5 days of age. This is common for both full-term and preterm newborns, especially those with a birth weight below 1500 g (6).

The most common investigations include USG examination of the head and abdomen, radiological examination of the chest, blood test, platelet count, coagulation test, blood gases, ionogram, glucose determination, blood, CFS and urine culture, infection indexes e.g., reactive protein C (CRP), granulocytic elastase, and ECG, or echocardiography and constant evaluation of the blood pressure. In order to differentiate the disease with adrenogenital syndrome and its types, assessment of adrenal hormones in the serum and a 24-hour collection of urine should be planned, depending on the newborn´s age.

It is particularly useful to assess plasma rennin activity (PRA), 17-hydroxyprogesterone (17-OHP), hydrocortisone and ACTH; the measurements can be done using immunoradometric and fluorometric techniques (6). Respective blood and urine determinations of VAM, dopamine, adrenaline and noradrenaline provide a functional assessment of the adrenal medulla, and, in association with urography, CT and MRI, facilitate a differential diagnosis of e.g., neuroblastoma.

A certain number of fatalities among the newborn in the course of shock, collapse, hyponatraemia and hypercaliaemia may be due to a complete or partial pituitary aplasia and/or brain hypoplasia, or its secondary damage. Not stimulated by control centres, the adrenal glands do not function, adequately, which, secondarily, leads to a disturbed ACTH concentration (feedback). The early neonatal period may also reveal the presence of familial Addison´s disease, described by Shepard et al. in 1959 (8). The patients show hydrocortisone deficiency and do not respond to ATCH stimulation, which, according to Migeon, is suggestive of a congenital ACTH receptor defect (4). The neonates with the syndrome present with shock, hypoglycaemia, and hyperpigmentation of the skin.

Aggravation of symptoms in the disease with age shows that it is rather a progressing degenerative process and not a congenital one. Not all cases of acute adrenal insufficiency are accompanied by shock, and the disease does not always have to develop fully. However, the disease has a very severe course when haemorrhage into the adrenal glands occurs and prognosis is not certain.

Below we present two cases treated in our Department.

N.C. (ref. no. 4759/158/95/F), a female infant, the product of a second pregnancy, was born spontaneously at 41 weeks of gestation with an Apgar score 9 and a body weight of 3220 g. The labour lasted 3 hours and 20 min. The immediate postnatal period was uneventful. Within 48 hours she developed projectile vomiting, and abdominal distension. Due to a presumed gastrointestinal obstruction breast feeding was stopped, intravenous fluids were given, and the patient was referred to our Department for further diagnosis and treatment.

On admission the patient´s cardiovascular and respiratory systems were normal; pulse rate 120/min; respiratory rate 34/min; blood pressure normal; meconium had been passed, peristalsis was normal, but the abdomen was markedly distended. Radiological examination did not show any evidence of gastrointestinal obstruction. Glucose concentration 41.3 mg%, sodium 138 mEq/l, potassium 5.9 mEq/l, calcium 1.11 mEq/l, total bilirubin 16 mg%, urea 40%, blood pH 7.55, paO 13.6, HCO 20, BE 5.3 mEq/l, BTA negative, CRP/++, CSF normal. Urine normal. Ht 54%, RBC 5600000, WBC 19,200, rods 1, segmented 63, acidphilic 5, lymphocytes 25, monocytes 5%.