What is a warning sign of ineffective adaptation to extrauterine life if noted when assessing a 24-hour-old breastfed newborn before discharge?

A. Apical heart rate of 90 beats/min, slightly irregular, when awake and active: A normal newborn heart rate ranges from 110 to 160 beats/min when awake. A rate of 90 beats/min in an active newborn suggests possible cardiorespiratory compromise or poor physiologic adaptation. Bradycardia at 24 hours of life warrants further evaluation before discharge. B. Harlequin color sign: Harlequin color change results from immature autonomic regulation of peripheral blood flow. It is a benign, transient finding commonly seen in newborns. It does not indicate impaired adaptation to extrauterine life. C. Weight loss representing 5% of the newborn's birth weight: Newborns commonly lose up to 7–10% of birth weight during the first few days due to fluid shifts and limited intake. A 5% weight loss at 24 hours is expected, especially in breastfed infants. This finding reflects normal physiologic adjustment. D. Acrocyanosis: Bluish discoloration of the hands and feet is common in newborns due to peripheral vasomotor instability. It is expected during the first 24–48 hours of life. Central perfusion and oxygenation remain adequate despite this finding.