What Does a Normal Complete Blood Count (CBC) Report Look Like for an Infant?

When taking your baby to the hospital, a complete blood count (CBC) is commonly performed. What are the normal reference values for this test? The details are as follows:

① Hemoglobin (Hb)

Hemoglobin is a protein within red blood cells responsible for oxygen transport. Iron, folic acid, and vitamin B12 are essential nutrients required for its synthesis. Normal hemoglobin levels are (120–160) g/L in adult males and (110–150) g/L in adult females.

Hemoglobin levels below the normal range indicate anemia. Elevated hemoglobin levels may occur in conditions such as polycythemia vera, or secondary to dehydration caused by vomiting or diarrhea.

② White Blood Cell (WBC) Count and Differential

The normal total WBC count in healthy adults is (4.0–10.0) × 10⁹/L. The differential percentages are as follows: neutrophils (Gran) 50%–70%, lymphocytes 20%–40%, monocytes 3%–8%, eosinophils 0.5%–5%, and basophils 0%–1%.

Clinicians typically first assess whether an infant has a systemic infection based on the total WBC count, then determine the likely type of infection (e.g., bacterial vs. viral) by analyzing the WBC differential.

③ Platelet Count

The normal platelet count ranges from (100–300) × 10⁹/L. Platelets play a critical role in hemostasis and blood coagulation. An elevated platelet count may predispose to a hypercoagulable state and increase thrombotic risk, whereas a low platelet count (thrombocytopenia) may lead to bleeding manifestations such as epistaxis, gingival bleeding, petechiae, or ecchymoses.