Final answer:
The risk associated with birthweights below 7.5 lb is mortality. Low birth weight infants face increased health risks such as disease susceptibility, higher infant mortality rates, as well as potential growth and developmental delays.
Step-by-step explanation:
The risk of mortality is associated with birthweights below 7.5 lb. Babies with low birth weight (< 2.5 kg or 5.5 lb) are at a higher risk for significant health issues compared to those born at a normal weight. These risks include increased susceptibility to diseases, higher chances of death in infancy, and the possibility of experiencing slow growth and developmental delays during early childhood. Furthermore, low birth weight can be caused by factors such as maternal undernutrition, intrauterine growth restriction (IUGR), and pre-term birth, all of which contribute to the baby's weight being below the average of 3.4 kg (7.5 lb) for full-term infants.