Platform
Company
Blood Gases
Review status
Currently under review
Pending specialist review and validation.
This test measures the partial pressure of carbon dioxide (pCO2) in blood drawn from the umbilical cord artery immediately after birth. The umbilical artery carries blood from the baby back to the placenta, so it reflects the baby’s respiratory status and acid–base balance at the moment of delivery.
It is typically performed as part of a cord blood gas panel along with pH, oxygen levels, and base excess. Together, these measures help clinicians understand how effectively carbon dioxide was being cleared through the placenta and whether there was respiratory stress around the time of birth.
pCO2 helps identify whether a baby experienced impaired gas exchange during labor or delivery. Elevated carbon dioxide can be a sign of respiratory acidosis, while lower levels can suggest increased ventilation or other causes. Interpreted alongside pH and other cord gas values, it helps distinguish respiratory from metabolic contributors to acid–base changes.
Your care team may order cord blood gases when there were concerns about fetal well-being during labor, a difficult or urgent delivery, preterm birth, or when a newborn needs extra support in the first minutes of life. Results can guide immediate care and provide important context for clinical decisions after birth.
Clinicians interpret your baby’s cord arterial pCO2 together with the cord pH, oxygen level, and base excess, plus the baby’s condition after birth. A result above the expected interval may point to reduced clearance of carbon dioxide and a respiratory component to acidosis. A result below the expected interval can reflect increased ventilation or, at times, an issue with how the sample was obtained or handled.
Small deviations can be temporary and may not indicate a problem on their own. If results are outside the expected interval, your team may repeat testing on a postnatal blood gas, monitor breathing and oxygenation, and tailor care to your baby’s clinical status. Ask your clinician to explain how the number fits with the full picture.
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.
Delays in clamping or analyzing the cord sample, air bubbles in the syringe, or improper storage can allow ongoing gas exchange and alter pCO2, leading to misleading results.
Cord venous blood has different gas values than arterial blood. Mislabeling or drawing from the wrong vessel can shift pCO2 and change the clinical interpretation.
Maternal hyperventilation, supplemental oxygen, or effects of general or regional anesthesia can influence placental gas exchange and the baby’s pCO2 at delivery.
Drugs such as opioids, magnesium sulfate, and beta‑agonists can affect fetal breathing efforts or placental blood flow, which may shift pCO2 at the time of birth.
Placental insufficiency, cord compression, meconium, or tight nuchal cord can impede gas exchange and raise pCO2, especially during prolonged or complicated labor.
Preterm infants or babies with congenital heart or lung conditions may have different physiologic responses, making pCO2 more variable and requiring careful context.
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