What outcome can result from a significant base deficit in umbilical cord arterial blood?

A significant base deficit in umbilical cord arterial blood indicates an accumulation of acid in the fetal bloodstream, which can signal a disturbance in the acid-base balance. This condition signifies that the fetus may be experiencing a state of metabolic acidosis, primarily resulting from inadequate oxygenation or increased metabolic demands.

When the base deficit is pronounced, it suggests that the buffering capacity of the blood is diminished, leading the fetus closer to a state of acidosis. This is a critical concern as it can impact the fetus's overall well-being and development. The progression to fetal acidosis may involve various deleterious effects on fetal organs, especially the brain, potentially leading to long-term neurological impairments if not promptly addressed.

In contrast, improvement in fetal cardiac function, reduced risk of neurological disorders, or stable oxygen saturation levels would not logically follow from a recognized significant base deficit. Such a deficit points to an imbalance that would likely compromise fetal health, making the linkage to acidosis the most direct and appropriate outcome to recognize in this context.