Renal disorders in the newborn

Prenatal diagnosis of renal disease is usually by fetal ultrasonograms that detect signs of obstructive uropathy. Fetal hydrops may occur with congenital nephrotic syndrome. Oligohidramnios occurs with severe urinary tract obstruction or renal agenesis, which is associated with pulmonary hypoplasia  (Potter's syndromes).


Clinical manifestations of renal disease vary with the type and severity of abnormality. Certain findings are indicative or suggestive of renal disease :

• Potter's syndrome

Potter's syndrome (renal agenesis and pulmonary hypoplasia) is a fatal condition that has typical physical abnormalities: flat nose, low set ears, receding chin, arthrogryposis and , often, a bell-shaped chest. With prolonged oligohydramnios due to other causes (eg obstructive uropathy, prolonged rupture of fetal membranes), the infants may show similar physical features and the severity of pulmonary hypoplasia varies from absent to severe, depending on duration and severity of oligohydramnios

• Dysmorphic features

Dysmorphic features sugesstive of renal disease include abnormal ears, single umbilical artery, hypospadius, anorectal abnormalities, polythelia (supernumerary nipples), vertebral anomalies and esophageal atresia (with or without tracheo-esophageal atresia)

• Lateral abdominal mass

Polycystic or multicystic kidneys, hydronephrosis, tumor (Wilm's tumor)

• Ascites

Ascites (urinary) due to rupture of obstructed urinary tract

• Suprapubic mass

Suprapubic mass may be an enlarged bladder secondary to urethral obstruction

• Abdominal wall defects

Exstrophy  of bladder, cloacal exstrophy, "prune belly" (absence of abdominal wall muscle due to fetal urinary ascites)

• Failure to palpate kidney

Unilateral renal agenesis, renal malposition, horseshoe kidney

• Hypertension

Hypertension is frequently due to renal disease. The commonest cause of neonatal hypertension is renovascular disease secondary to clots or emboli from a "high"umbilical arterial catheter

• Anuria or oliguria

However, only 90% of normal infants urinate in the first 24 hours after birth, therefore, 10% of normal infants do not urinate on the first day


The presence of any of the above signs should alert one to the possibility of renal dysfunction and raise the possibility of further diagnostic work-up including, in addition to careful measurements of intake and urine output, serum creatinine, blood urea nitrogen, electrolytes and abdominal ultrasound.