Platform
Company
Complete Blood Count
Review status
Currently under review
Pending specialist review and validation.
This test measures the percentage of white blood cells that are monocytes in a sample of your newborn’s umbilical cord blood. Monocytes are immune cells that help fight infections and clear damaged tissue. The result is a relative value, showing what share of all white blood cells are monocytes at the time of sampling.
It is typically performed as part of a complete blood count with differential. Laboratories use automated analyzers to classify the different white blood cell types and calculate the monocyte percentage, sometimes confirming results with a manual smear review if needed.
The monocyte percentage can help your baby’s care team assess for possible infection, inflammation, stress related to delivery, or certain blood and bone marrow problems. It is often ordered alongside other tests when there are risk factors around birth, such as maternal infection, fever, prolonged membrane rupture, growth concerns, or prematurity.
Clinicians interpret the monocyte percentage together with other white blood cell types, red blood cells, platelets, and your baby’s signs and symptoms. Shifts in the balance of cells can support or argue against infection or inflammatory disease, guide decisions about cultures or antibiotics, and help monitor response to treatment.
A higher or lower monocyte percentage by itself does not confirm a diagnosis. Around the time of birth, the mix of white blood cells can fluctuate as your baby transitions to life outside the womb, and small changes are often normal.
If your baby’s result is unexpected, the clinician may repeat the test, review a blood smear under the microscope, or order other studies such as cultures or inflammatory markers. Results are interpreted in context, including gestational age, how the delivery went, and any medicines you or your baby received. Ask your care team what the pattern means for your baby and whether any follow-up is needed.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
White blood cell proportions can shift quickly after birth. Whether the cord sample is taken immediately or after a delay can influence the monocyte percentage seen on the report.
Cord blood is collected in an anticoagulated tube. Clotting, dilution with non-blood fluids, or prolonged delay before analysis can alter cell counts and trigger instrument flags that affect the reported differential.
Prematurity, labor stress, and mode of delivery can influence circulating white blood cells. These physiologic factors may shift the relative balance of monocytes compared with other cell types.
Maternal fever, infection, inflammation, or medicines such as corticosteroids can affect the newborn’s white blood cell distribution, sometimes lowering or raising the monocyte proportion.
Congenital or perinatal infections, inflammatory disorders, or hypoxic stress can change monocyte trafficking and production, leading to higher or lower percentages in cord blood.
Automated hematology analyzers classify cells using optical or impedance methods. Unusual cells or instrument flags may prompt a manual differential, which can slightly change the reported percentage.
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