What percentage of weight loss is considered physiological for term infants?

In term infants, a physiological weight loss of up to 10% is considered normal during the first few days after birth. This is largely due to fluid loss, as newborns lose excess extracellular fluid after transitioning from the intrauterine to the extrauterine environment.

Typically, this weight loss happens within the first week of life, after which infants should begin to regain their birth weight. Monitoring this process is crucial because while a weight loss of up to 10% is typical, exceeding this percentage can indicate underlying issues such as feeding difficulties, dehydration, or other health concerns.

The rationale for considering 10% as the threshold highlights the importance of maintaining a balance between understanding the natural process of adaptation in the newborn and recognizing when interventions may be necessary to support healthy growth and development. As such, weight loss beyond this 10% may require closer evaluation and management, while weight loss within the 5-10% range is typically viewed as a normal physiological response.