Pregnancy Nutrition Surveillance System - Infant Health Indicators

Article Index


Infant Health Indicators


  • Low Birthweight (<2500 grams or < 5.5 pounds) is the single most important factor affecting neonatal mortality and is a determinant of post-neonatal mortality (NAS 1985). Infants weighing less than 2500 grams are almost 40 times more likely to die during their first four weeks of life than are infants of normal birthweight (Paneth 1995). Although the infant mortality rate in the United States declined from 26 per 1000 live births in 1960 to 7 per 1000 live births in 1999, the nation ranks behind most industrialized countries for this health indicator. Low birthweight infants who survive are at increased risk for health problems ranging from neurodevelopmental handicaps to lower respiratory tract conditions (Paneth 1995).
  • High Birthweight (HBW) is defined as a birthweight of >4000 grams or 8.8 lbs. This reflects the WIC Nutrition Risk Criteria (IOM, 1996) which is based on a generally accepted intrauterine growth reference > the 90th percentile weight for gestational age at birth (ACOG Technical Bulletin, 1991). High birthweight usually occurs in full-term or post-term infants but can occur in preterm infants. HBW puts infants at increased risk for birth injuries such as shoulder dystocia and infant mortality rates are higher among full-term infants who weigh more than 4000 grams than infants weighing between 3000 and 4000 grams. (ACOG technical bulletin).

Preterm Birth refers to delivery before 37 weeks gestation. Preterm births are the largest contributor to neonatal, infant and perinatal mortality in the U. S. and can be minimized by preventing problems like anemia and inappropriate weight gain through nutrition intervention. (IOM, 1990, 1996) Other factors related to increased risk of preterm delivery include low income, ethnic background (particularly black), young age, smoking, and low education attainment. (IOM, 1996)

Full Term Low Birthweight refers to infants born at or after 37 weeks weighing less than 2500 grams. This indicator is one of several used to diagnose intrauterine growth retardation or fetal growth restriction. (IOM, 1996) In these infants gestational age is not the issue because the pregnancy is complete; however, poor maternal nutrition is cited as one of the many causes of full term birthweight. (Kessel, 1978, IOM 1996) An infant's size at birth is very important as fetal growth restriction contributes to the risk of respiratory distress, hypoglycemia and other problems. (IOM, 1996) 

Breastfeeding Initiation reports the number of infants ever breastfed or fed breastmilk. The nutritional, immunologic, allergenic, economic and psychological advantages of breastfeeding are well recognized. Breastfeeding is nutritionally superior to any alternative infant feeding method and provides immunity to many viral and bacterial diseases; enhances infants' immunologic defenses; prevents or reduces risk of respiratory and diarrhea diseases; promotes correct development of jaws, teeth and speech patterns; decreases tendency toward childhood obesity and facilitates maternal infant attachment (Jacobi and Levin, 1993; AAP 1997).