Low birthweight in newborns

What is low birthweight?

Babies are weighed within the first few hours after birth. The weight is compared with the baby's gestational age and recorded in the medical record. A birthweight less than 5 pounds, 8 ounces is diagnosed as low birthweight. Babies weighing less than 3 pounds, 5 ounces at birth are considered very low birthweight.

The average newborn weighs about 7.6 pounds and about 7.6 percent of all newborns in the U.S. have low birthweight. The overall rate of these very small babies is increasing, primarily because of the increase in multiple birth babies, who tend to be born earlier and weigh less. More than half of multiple birth babies have low birthweight.

Why is low birthweight a concern?

If your baby has a low birthweight, she may be at increased risk for complications. Her tiny body is not as strong, and she may have a harder time eating, gaining weight and fighting infections. Because she has so little body fat, she may have a hard time staying warm in normal temperatures.

Because many babies with low birthweight are also premature, it is can be difficult to separate the problems due to the prematurity from the problems of just being so tiny. In general, the lower a baby's birthweight, the greater the risks for complications. The following are some of the common problems of low birthweight babies:

Care for low birthweight

The Boston Children's Hospital Infant Follow-Up Program is designed for infants born very prematurely, who weigh less than 3.3 lbs and are at high risk for development and motor delays and other problems resulting from prematurity. Our program follows children from the time of discharge until they reach age 3 to 4.

The multi-disciplinary Infant Follow-Up team includes pediatricians, neonatologists, pediatric psychologists, physical therapists, social workers and if needed, pediatric neurologists.