1. What is the IT Ratio?

The IT (Immature to Total neutrophil) Ratio is a marker used in neonatal intensive care to assess the severity of infection in newborns. It compares the number of immature neutrophils to the total neutrophil count.

2. How Does the Calculator Work?

The calculator uses the IT Ratio formula:

Where:

• Immature Neutrophils — Band forms and earlier neutrophil precursors (x10³/µL)
• Total Neutrophils — All neutrophils (mature + immature) (x10³/µL)

Explanation: The ratio is expressed as a percentage, with higher values suggesting more significant infection or inflammation.

3. Importance of IT Ratio in NICU

Details: In neonates, especially preterm infants, the IT ratio is a valuable tool for early detection of sepsis when clinical signs may be subtle. A ratio >0.2 (20%) is often considered abnormal.

4. Using the Calculator

Tips: Enter both immature and total neutrophil counts in x10³/µL. Both values must be valid (≥0 and total neutrophils >0).

5. Frequently Asked Questions (FAQ)

Q1: What is a normal IT ratio in newborns?
A: Typically <20% in healthy term infants. Values >20% suggest infection, though thresholds may vary by institution.

Q2: How does IT ratio compare to I/T ratio?
A: They are the same measurement, just written differently (IT vs I/T).

Q3: When should IT ratio be measured?
A: When neonatal sepsis is suspected, along with other markers like CRP, complete blood count, and clinical assessment.

Q4: Are there limitations to IT ratio?
A: Yes, it can be elevated in non-infectious conditions like perinatal stress, and may be less reliable in extremely preterm infants.

Q5: How often should IT ratio be repeated?
A: Serial measurements (every 12-24 hours) can help monitor response to treatment in confirmed sepsis.