What percentage of total body water is typical for a premature newborn?

For a premature newborn, the typical percentage of total body water is around 85%. This high percentage is largely due to the fact that premature infants have not yet fully developed the ability to concentrate and conserve body fluids, leading to a higher proportion of water in their body composition compared to full-term infants who typically have around 70-75% body water.

The increased body water percentage in premature newborns is essential for their physiological functions and overall development, as it aids in the distribution of nutrients and helps in regulating body temperature. As they grow and mature, their body water percentage gradually decreases as their body fat increases and their renal function improves. This understanding of hydration in premature infants is crucial for managing their care in neonatal settings, as they are at higher risk for dehydration and electrolyte imbalances.