3. Weighing Infants: Equipment and Preparation

The specific recommendations for equipment necessary for accurate and reliable weighing are presented in the companion Accurately Weighing and Measuring: Equipment module. It is assumed that the scale has appropriate precision of 0.01 kg or 1/2 oz. for weighing an infant and is calibrated.

It is important that the infant be weighed using procedures similar to those used to collect the data for constructing the charts. It is also important to use consistent procedures.

The NHANES weight data were collected from infants who were wearing clean disposable diapers.Infants in the WHO Multicentre Growth Reference Study were weighed nude. Weighing infants with too much clothing is one of the most frequent sources of error in infant weight measurements. This causes infants to be ‘weighed heavy’; an infant will appear to weigh more than he actually does.

			Infant is weighed nude or in a clean diaper on a calibrated beam or electronic scale