What Is Late Metabolic Acidosis in a Newborn?

Late metabolic acidosis is a condition affecting infants, in which the acid to alkaline ratio of the blood is not balanced. This pH balance disorder is most common in premature infants and is characterised by slowed growth and development.


Unlike early metabolic acidosis, which is an acid disorder at birth caused by respiratory disease or airway blockage, late metabolic acidosis is a condition which develops later in the newborn's life. It generally occurs during the second to third weeks of life in preterm neonates.

pH Balance

The human body has a delicate balance between the acids and bases in the blood which is called the pH balance. Healthy blood has a pH level of 7.35 to 7.45 when the kidneys are functioning properly. In late metabolic acidosis, the pH balance in the blood becomes too low because the infant cannot excrete acid adequately via the kidneys. As the pH balance becomes disturbed, the infant's growth rate is slowed.


The disorder often improves or completely resolves after three weeks of age due to the fact that the premature infant's renal system becomes more developed and is able to excrete acid in the manner of full-term infants.


The disorder has been found to be linked directly to premature infants' formula. When a premature infant is given a standard baby formula, the protein content of the formula can be too high for the infant to maintain acid homeostasis.

Reduced Instances

Late metabolic acidosis rates have significantly declined with the advent of lower protein formulas specifically designed for premature infants.