As with everything else in the baby’s body, its blood gases are highly unstable. This is why, in order to ensure the best cord blood quality, that same blood has to go undergo countless tests and regulations before it can be stored and ultimately used for other purposes. This is where cord blood gas analysis plays a major role. The easiest way to assure that everything is okay with the blood is to make sure everything goes smoothly during pregnancy when it comes to the fetus and the later on – the baby.
How Babies Breathe
Fetuses depend entirely on their mothers when it comes to breathing. This means that it gets its oxygen from the mother and disposes the CO2 back to her bloodstream. Breathing isn’t exactly the same inside the womb. It isn’t associated with chest movement and inspirations and expirations but is rather a chemical reaction occuring in the placenta. The placenta is the organ that connects the baby to the uterine wall allowing for better nutritional contact. It is also responsible for gas exchanges and whenever there are fluctuations in the gas analysis it is the first part of the mother-baby connection to be checked.
The oxygen-rich blood coming from the mother disperses into the placenta in the form of capillaries. Later on, those capillaries converge into a the umbilical vein which goes to the baby’s heart. From there, it goes to every part of the baby’s body. Once the blood oxygen levels drop they are escorted out of the baby via the two umbilical arteries. Then, inside that same placenta that started the whole thing, the high on carbon dioxide blood diffuses into the mother’s bloodstream and lastly the mother exhales the excessive CO2. Basically the only two processes that control the cord blood gases concentrations are the oxygen intake and the outgoing carbon dioxide which is the end product of the baby’s metabolism.
Relation Between Gas Levels And Cord Blood
Now, you might be wondering why are gas levels so important to baby cord blood. Well, not only that it heavily influences the storing options for the blood, but it also determines its healing factors down the road.
As we pointed out on our main page, cord blood has high levels of stem cells and WBC (white blood cells). Those two type of cells are hypersensitive to blood oxygen levels. This is why every time cord blood is taken for storing it has its gases analyzed. Also the overall health of the baby during its 9 months inside the woman’s womb further determine the quality of the cord blood. This is why conditions in the mother such as anemia, hypertension, hypoxia, and other, can be fatal to the whole process of cord blood storing.
When trying to diagnose what exactly is going on there are two leading clues:
- Blood in the umbilical vein indicates the status of the uterus and the placenta
- Blood in the umbilical arteries reflects the overall status of the fetus.
The stem cells, which are our primary goal here, can be drastically reduced if the baby has suffered an oxygen-depriving event (hypoxic or anoxic event). We can determine whether such thing has occurred by examining the umbilical artery blood. We use it because it is the one coming from the baby and can give us information about the metabolic state of its body. If the artery blood has acidosis it hints that there is an excess of anaerobic metabolism happening. This means that the baby’s body is working with less than ideal oxygen levels. Hypoxic conditions can lead to HIE (hypoxic ischemic encephalopathy) in the baby which will result in permanent brain damage. It also leads to disorders such as Cerebral Palsy and seizures later on in life.
To learn the different uses and advantages of stem cells, check out our dedicated article on the topic.
The Main Cord Blood Gases Interpreted
High pCO2 levels
Respiratory acidosis/alkalosis is defined by the level of involvement of pCO2 in the acid/base status of the baby. Elevated pCO2 levels mean that the baby is producing more CO2 than his body can handle and that can be eliminated through the mother-baby circulation. Accumulation of CO2 most often happens due to umbilical cord compression. This is an acute state that prevents movement of blood to and from the baby. It can lead to serious damage or even be fatal.
High HCO3 levels
An increase in the bicarbonates (HCO3s) with an elevated CO2 and normal pH levels is called a compensated respiratory acidosis. HCO3 is responsible for neutralizing acidity in the blood therefore its role is to keep carbon dioxide making blood too acidic.
High pO2 levels
A lot of oxygen is rarely a huge issue but in babies it means that the baby’s body isn’t absorbing the delivered oxygen well. This can lead to tissue damage and ischemic type of processes. Furthermore it can indicate some sort of heart/kidney issue.
Here are the blood norms with which laboratories work when testing cord blood before storing it. Have in mind that apart for storing purposes this analysis gives precious information about the baby’s and mother’s health.
Normal Values In Cord Blood Samples From Term Newborn
- pH – 7.18 – 7.39
- pO2 – 6 – 31 mmHg
- pCO2 – 33 – 65 mmHg
- HCO3 – 17 – 27 mmol/L
Normal Values In Cord Blood Samples From Preterm Newborn
- pH – 7.14 – 7.4
- pO2 – 5 – 30 mmHg
- pCO2 – 32 – 69 mmHg
- HCO3 – 16 – 27 mEq/L
Ultimately we want our babies to be as healthy as possible. This will ensure a great life ahead of them but also a very potent cord blood which can be stored and used to treat any future diseases in the baby itself and its relatives.