Low birth weight is defined as a newborn weighing less than how many pounds (2,500 g)?

• A. Less than 5.5 lb (2,500 g)
• B. Less than 6.5 lb
• C. Less than 7.5 lb
• D. Less than 4 lb

Answer: (A)

Low birth weight is defined by a specific cutoff in weight: an infant weighing less than 2,500 grams, which is about 5 pounds 8 ounces. This threshold is used to flag babies at higher risk for respiratory problems, infections, and other complications, guiding closer monitoring and care. The option that states five and a half pounds corresponds exactly to 2,500 grams, so it matches the standard definition. The other weights are either above that threshold (6.5 lb and 7.5 lb) or well below it (4 lb), so they do not define low birth weight.