Common Labs

Ionized calcium

• Preterm (1.5 kg): 1-1.56 mM/L > 24 HOL

• Term: > 1.1 mM/L after 24 HOL

Serum phosphorus

• Preterm: 2 - 2.5 mM/L (6.2-7.8 mg/dL) 

• Term: 1.9 - 2 mM/L (6.1-6.2 mg/dL) 

• Infants >2 months of age: 1.8-1.9 mM/L 

Serum potassium

• Preterm: 3.0–6.0 mmol/L

• Newborn: 3.7–5.9 mmol/L

• Infant: 4.1–5.3 mmol/L

• 21-OH Deficiency (Salt Wasting CAH)

  • No cortisol or aldosterone

  • Hyponatremia

  • Hyperkalemia

  • Hypotension

• 11-OH Deficiency

  • Excess deoxycorticosterone (aldosterone analog) and excess deoxycortisol (cortisol analog) due to positive feedback loop

  • Normal sodium

  • Possibly hypokalemia

  • Hypertension

• 17-OH Deficiency

  • Excess aldosterone

  • Hypokalemia

  • Hypertension

  • Ambiguous male genitalia