What defines metabolic acidemia?

Metabolic acidemia is characterized by an increased concentration of hydrogen ions in the blood, which lowers the pH and leads to an acidotic state. This condition can occur due to various reasons, one of the most common being the buildup of lactic acid, often resulting from anaerobic metabolism when the oxygen supply is limited.

In the context of fetal monitoring, metabolic acidemia indicates that the fetus may not be receiving adequate oxygen, leading to a stress response characterized by the increased production of lactic acid. This can be critical in fetal assessment, as it helps health professionals identify potential distress and take appropriate actions to stabilize the situation.

The other options do not accurately represent the condition of metabolic acidemia. High levels of oxygen and glucose would actually be beneficial and not indicative of acidemia. A decrease in fetal heart rate can be a sign of various complications but does not specifically define metabolic acidemia. Increased alkalinity of fetal blood, or metabolic alkalosis, is the opposite of what is seen in metabolic acidemia, highlighting a higher pH rather than a lower one due to excess hydrogen ions.