Globally, approximately one in six neonates is born at a low birth weight (<2500 grams). This is an important predictor of neonatal morbidity and mortality whether the neonate is premature or small due to intrauterine growth restriction. Weighing allows extra attention to help diagnose pathologies which are much more prevalent in low birth weight infants. For instance, infant respiratory distress syndrome is much more common among infants of very low birth weight. Knowing the birth weight is low allows careful checks to see if the neonate has respiratory distress syndrome which will be diagnosed clinically.
Mechanism of Action
Electronic and spring scales are the most common tools for determining birth weight. Electronic scales require a power source and typically use a strain gauge whose resistance varies with very small, elastic deformation under load. Spring scales are typically simpler, less expensive, and do not require power. However, these devices' analog display and requirement for calibration make them less advantageous where high accurracy is valuable.
In community health settings, the caregiver places the baby in a sling of known weight and hangs the sling from a calibrated scale. The spring elastically deforms under the load, giving a readout. In clinical settings, accurate knowledge of an infant's weight can be used to track hydration, nutrition, and waste evacuation.
Current use in High-resource settings
Electronic scales with resolution of 2g are common in high-resource settings. For infants in intensive care, the electronic scale may be integrated into the incubator so that the patient need not be moved to be weighed. Nearly all babies are weighed at birth and periodically for check ups. Sick and premature newborns are typically measured multiple times per day.
Application in Low-resource settings
Traditional Birth Attendants (TBAs) may approximate weight by feel, but rarely carry weight measurement devices. Skilled birth attendants are more likely to carry spring scales to deliveries, or use them in clinics. Hospitals frequently have analog or digital tabletop scales to weigh neonates.
Related technologies in development