Platform
Company
Complete Blood Count
Review status
Currently under review
Pending specialist review and validation.
This test measures the amount of hemoglobin in blood taken from the umbilical cord at birth. Hemoglobin is the protein inside red blood cells that carries oxygen to tissues and helps remove carbon dioxide. Using cord blood allows your baby’s care team to assess oxygen-carrying capacity right away without an extra needle stick.
Your baby’s result is interpreted alongside gestational age, delivery details, and the immediate newborn transition. Cord blood values naturally differ from those in older infants and adults, and can be influenced by when the cord is clamped and how the birth unfolded.
Cord blood hemoglobin helps identify anemia or unusually concentrated blood in a newborn, both of which can affect oxygen delivery, blood flow, and early adjustment after birth. The test is often used when there are concerns about placental bleeding, maternal conditions, multiple gestation, growth restriction, or signs such as jaundice or breathing difficulty.
Early recognition guides the need for observation, hydration, evaluation for hemolysis or blood loss, and occasionally transfusion. Because the sample is obtained immediately after delivery, it helps the team decide whether additional testing or closer monitoring in the nursery or neonatal unit is appropriate.
A lower-than-expected hemoglobin can be due to blood loss before or during delivery, reduced red blood cell production, or increased breakdown of red cells. A higher-than-expected result can be seen with delayed cord clamping, maternal diabetes, placental insufficiency, or residence at high altitude. Your baby’s clinicians will consider the number together with symptoms, the physical exam, and related tests such as a complete blood count, bilirubin, and a blood smear.
If results fall outside the usual range, next steps may include repeating the test after the immediate transition period, checking hydration and feeding, and looking for causes such as infection, antibody-mediated hemolysis, or twin-to-twin transfusion. Many findings are mild and improve with routine care. If a more serious issue is suspected, your team will discuss treatment options and follow-up.
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.
Delaying or hastening cord clamping changes blood volume that flows to the newborn, which can raise or lower cord hemoglobin compared with immediate clamping.
Clotting in the sample, dilution by tissue fluid, or contamination can alter measured hemoglobin. Properly filling and mixing the tube helps ensure accuracy.
Prematurity, post-term birth, or a stressful delivery can influence red blood cell levels and distribution, affecting cord hemoglobin at the moment of birth.
Diabetes, hypertension, smoking, and placental insufficiency can affect placental blood flow and fetal red cell production, shifting newborn hemoglobin.
Living at high altitude stimulates fetal red blood cell production, which may increase cord hemoglobin relative to values seen at sea level.
Hemolytic disease, fetomaternal hemorrhage, twin-to-twin transfusion, or internal bleeding can lower cord hemoglobin and prompt additional evaluation.
References