Postnatal weight change is a common occurrence in newborns. A tool exists to quantify the degree of this change as a percentage. This quantification is obtained by calculating the difference between the birth weight and the lowest recorded weight after birth, then dividing that difference by the birth weight and multiplying by 100. For example, a baby born at 3500 grams who reaches a lowest weight of 3200 grams would have a calculated value of approximately 8.6%.
The value derived from this calculation is a critical parameter in assessing the well-being and hydration status of neonates. It provides clinicians with an objective measure to evaluate the adequacy of feeding and identify potential complications such as dehydration or insufficient caloric intake. Historically, monitoring weight change has been a fundamental aspect of newborn care, evolving from simple manual measurements to incorporating standardized calculations for improved accuracy and consistency.