The nurse compared the birth weight of a 3-day-old with her current weight and determined the infant had lost weight. What is the most appropriate intervention by the nurse?

It is completely normal for newborns to lose weight during the first few days of life. Most newborns lose approximately 5 to 10 percent of their birth weight within the first three to four days, primarily due to loss of meconium, urine, and normal fluid shifts following delivery. Birth weight is typically regained by 10 to 14 days of age. A 3-day-old who has lost some weight is therefore experiencing an expected physiological phenomenon, and the most appropriate nursing intervention is to do nothing because this is a normal occurrence, while continuing to monitor the infant's weight and feeding patterns. Decreasing the interval between feedings might be appropriate if the weight loss exceeds 10 percent of birth weight or if the infant shows signs of poor feeding, but as a blanket intervention for any weight loss at day 3, it is not the most appropriate first action. Switching formula would not be indicated without specific clinical reasons, and changing formula unnecessarily could disrupt feeding. Immediately reporting this to the pediatrician is not warranted for expected physiological weight loss, as this would constitute an overreaction to a normal finding and could unnecessarily alarm the family.