There is no single, generally accepted set of clinical criteria that define hypoglycemia in newborns across all circumstances. Individual characteristics of the newborn (e.g. weight, gestational age, maternal DM and/or medications, fetal distress) make a big difference as to whether the newborn has clinically significant hypoglycemia in the medical sense.
Below are links to different criteria with relevant comments.
"Hypoglycemia” may occur in up to 10% of healthy term newborns, especially in the first 24 to 48 hours after birth. The definition of hypoglycemia varies because a single specific glucose value does not inherently indicate symptomatology in the patient.* Blood glucose values may be as low as 30 mg/dL (1.67 mmol/L) in the first 1 to 2 hours after birth in healthy term neonates, rising to values similar to adults within 48 to 72 hours with established feeding cycles. Many infants who have “low” blood glucose values are without risk factors and are clinically asymptomatic. Others exhibit poor feeding or have longer intervals without substantial feedings but are clinically asymptomatic or do not exhibit hypoglycemia. These findings point to an incomplete understanding of the mechanisms of blood glucose regulation in the newly born infant."
"Hypoglycemia is the most common metabolic disturbance occurring in the neonatal period. Screening at-risk infants and the management of low blood glucose levels in the first hours to days of life is a frequent issue in the care of the newborn infant. Yet, a clear definition of neonatal hypoglycemia is lacking."
Neonatal hypoglycemia, defined as a plasma glucose level of less than 30 mg/dL (1.65 mmol/L) in the first 24 hours of life and less than 45 mg/dL (2.5 mmol/L) thereafter, is the most common metabolic problem in newborns.
You will note that the third reference and the first are contradictory. Individual facilities may select one criteria set by policy. If this is the case, we should follow the individual policy as established by the facility.
*Do not code this condition based on lab results alone. Capture documentation that this parameter was tracked, and, if applicable, treated.