Changes in body water distribution during the first two weeks of life

Abstract

Measurements of total body water, extracellular volume, and plasma volume carried out on 46 newborn full-term and premature infants have yielded the following information Premature infants in the first few days of life showed a marked instability of the control of total body water. When present, this instability affected primarily the intracellular volume. A day-to-day study indicated that during the first 3 days the extracellular volume rose. The evidence suggested that this increase was largely due to transfer of water from the intracellular space. These findings were to some extent confirmed by changes observed in MCHC. It is suggested that the early expansion of extracellular volume may partly account for a coincident rise in the plasma volume.