Abstract

The total body water content was measured by the deuterium oxide dilution method in 55 neonates admitted to hospital for surgical treatment within 90 hours of birth. The mean total body water of the whole group was 77·03 ± 0·62 (SEM)% of the body weight (range 67·4 to 88·6%), or 1·974 ± 0·005 (SEM) litres (range 1·010 to 2·830 litres). Over a range of body weights from 1·160 to 3·851 kg, total body water content expressed as a percentage of body weight decreased by 5% per kg rise in body weight, but when expressed as litres per kg body weight it increased by 737 ml for each rise of 1 kg in body weight. There was a small difference in water content between babies with obstruction of the alimentary tract and those with other nonobstructive lesions, which was not statistically significant.