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On this page, we will explain what cord blood gas analysis is and how the results of this test can be used to determine whether the baby suffered a birth injury during delivery as a result of oxygen loss.
Umbilical cord blood gas analysis assesses the fetal metabolic state at the time umbilical circulation ceases during childbirth. Clamping the umbilical cord is a standard practice after delivery, and research has shown that this test is crucial for evaluating a newborn’s health.
This analysis helps doctors determine if the baby sustained any birth injuries during delivery by indicating whether the baby is experiencing acidosis, a condition that can signal a hypoxic-ischemic event.
Cord blood gas results are often used as evidence in birth injury medical malpractice cases, helping both attorneys and doctors assess the extent of harm to the child and establish whether negligence contributed to the injury.
When our birth injury attorneys review new cases, one of the first things we examine is the baby’s cord blood gas levels. However, you don’t need to be pursuing a malpractice case to want to understand your child’s blood gas values and their implications.
If you believe you have a potential birth injury case in the U.S., call us at 800-553-8082 or request an online case review.
About Cord Blood Gas Analysis
After a baby is born, the blood in the umbilical cord artery retains gord blood gases which can provide key information about what happened to the baby during delivery and whether the baby suffered oxygen deprivation.
Cord blood gas analysis is a laboratory test performed on blood from the umbilical cord at the time of birth to assess the baby’s acid-base status and oxygenation. To perform the test, doctors clamp the umbilical cord seconds after the baby is delivered. The blood trapped in the cord is then tested to measure the acidity levels. This can help determine whether the newborn experienced any oxygen deprivation or metabolic stress during labor or delivery.
This analysis of cord blood gas is usually the most accurate indicator of whether hypoxia or ischemia occurred during the labor and delivery process.
How are Cord Blood Gases Measured?
To measure cord blood gases, the umbilical cord must be clamped immediately after the baby comes out. The blood in the cord can then be extracted and sent for laboratory analysis. There are two types of cord blood that can be sampled:
Arterial blood: Taken from the umbilical artery, which reflects the baby’s condition and is more commonly used for interpretation.
Venous blood: Taken from the umbilical vein, which reflects the maternal condition and placental function.
Key measurements in cord blood gases include:
pH: Indicates the acidity or alkalinity of the blood. Low pH suggests acidosis, which could be caused by oxygen deprivation.
Partial pressure of carbon dioxide: Reflects how well the baby is eliminating CO₂, a measure of respiratory function.
Partial pressure of oxygen): Indicates the oxygen levels in the blood.
Base excess/deficit: Measures the amount of buffering agents (like bicarbonate) in the blood, indicating the metabolic component of acidosis or alkalosis.
The most important measurements in an arterial cord blood gas analysis are the baby’s pH level and base deficit, both of which help assess the blood’s acidity in the umbilical cord. These values are crucial in identifying acidosis, a condition where excess acid builds up in the blood.
Acidosis is typically indicated by a lower pH and a higher base deficit. Poor cord blood gases at birth, marked by these changes, signal potential acidosis and serve as a warning sign of hypoxia (lack of oxygen) during delivery.
Why pH Levels are So Important
Cord pH provides a crucial measure of the baby’s acid-base status when the umbilical cord is cut, offering insight into the fetus’s oxygenation just before delivery.
A normal arterial pH in a newborn indicates sufficient oxygenation and blood flow during labor and delivery. In contrast, a low pH (acidosis) may suggest that the baby experienced hypoxia (reduced oxygen supply) or ischemia (reduced blood flow) before, during, or after delivery.
While pH levels at birth are fairly good indicators of a child’s condition, they are not perfect predictors of long-term outcomes. Severe acidosis is linked to higher risks of neonatal complications, such as neurological impairment, and in extreme cases, mortality. Monitoring pH helps identify newborns at risk for adverse outcomes, allowing for timely intervention and close observation.
Interpreting PO2 Cord Blood Gas Levels
A PO2 level at birth is an important indicator in neonatal care, as it reflects the amount of oxygen in the baby’s blood at the time of delivery. This measurement is obtained from the umbilical cord immediately after birth.
PO2 is usually analyzed as part of a broader arterial blood gas (ABG) test, which also measures pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3), and base excess. This comprehensive evaluation helps assess the newborn’s respiratory and metabolic function.
PO2 High Meaning
Elevated PO₂ levels at birth may indicate over-oxygenation of the fetus. While oxygen is vital for survival, too much can be harmful, particularly for premature infants. A high PO₂ in the arterial cord blood suggests that the baby received more oxygen than normal before birth. Excessive oxygen exposure can lead to complications such as retinopathy of prematurity (ROP) and oxidative stress, which can damage cells.
If high PO₂ levels are detected, healthcare providers will evaluate the newborn’s overall health and oxygenation status. The goal is to maintain PO₂ within a target range that ensures sufficient oxygenation without reaching harmful levels. Management may involve adjusting respiratory support (if needed) and closely monitoring oxygen levels to prevent oxidative damage, depending on the baby’s condition and the underlying cause.
PO2 Low Meaning
A PO₂ level significantly below the expected range for a newborn’s gestational age and the time after birth may indicate hypoxemia. In newborns, hypoxemia can result from conditions such as respiratory distress syndrome, congenital heart defects, retained lung fluid, or inadequate lung expansion.
If the pH is low but PCO₂ remains normal or low, this points to metabolic acidosis, suggesting a metabolic issue. Possible causes include infection, poor tissue perfusion leading to lactic acid buildup, or other metabolic disorders.
As with any newborn test, PO₂ levels should be interpreted in the context of the baby’s overall health, including respiratory effort, skin color, and other vital signs. Additional factors, such as the method of oxygen delivery (if used) and the altitude of the location, must also be taken into account.
Acidosis and Birth Injuries
Acidosis has two main types: respiratory acidosis and metabolic acidosis. Respiratory acidosis results from impaired lung function, causing carbon dioxide to accumulate in the lungs and bloodstream, leading to increased acidity.
Metabolic acidosis occurs when the body’s acid levels rise due to impaired kidney function or other metabolic imbalances. Both types of acidosis can cause neurological damage, which may be temporary or permanent depending on the extent of the injury. However, metabolic acidosis is generally linked to more severe outcomes.
Cord Blood Gases in Birth Injury Malpractice Cases
Cord blood gas results can be crucial evidence in birth injury litigation. If a baby suffers from hypoxia leading to a birth injury, cord blood gas results may help validate the plaintiff’s claim.
Malpractice attorneys and medical experts often use these results to demonstrate the extent of damage during delivery by referencing specific pH and base deficit levels. On the other hand, cord blood gases can also be used in defense against birth injury lawsuits. If the newborn has a birth injury but the blood gases are normal, an obstetrician may argue that the injury did not occur during delivery and was not due to negligence.
There are, however, reasons why a baby might have normal cord blood gases yet still suffer a hypoxic brain injury. For instance, the baby might have experienced poor circulation and perfusion just before birth or sustained a physical head injury during delivery.
Additionally, errors in blood storage and analysis can impact results. Studies show that up to 19% of cord blood gas samples may be invalid due to human error. Misinterpretation of blood gas data can also result in overestimating or underestimating the level of hypoxia.
A medical malpractice attorney handling birth injury cases involving cord blood gases must have a deep understanding of pH and base deficit levels. They should closely examine how the blood gas samples were taken and identify any technical errors that could invalidate the results. Collaboration with medical experts is also critical to establish the cause and timing of the birth injury.
Acidosis is assessed by a combination of low blood pH and a high base deficit. It can be calculated using measurements of pH, carbon dioxide (CO₂) pressure, and hemoglobin levels.
Low pH due to acidosis can lead to conditions such as hypoxic-ischemic encephalopathy, periventricular leukomalacia, seizures, brain hemorrhages, and cerebral palsy. In severe cases of metabolic acidosis, it can cause multi-organ failure and even death.
The primary cause of acidosis is insufficient oxygen supply from the placenta to the baby.