Plurality Characteristics, United States
The following table shows the number, percent, weight, and mean age of infants, according to birth plurality.
1. Very preterm is less than 32 completed weeks of gestation.
2. Preterm is less than 37 completed weeks of gestation.
3. Very low birthweight is less than 1,500 grams.
4. Low birthweight is less than 2,500 grams.
Source: National Center for Health Statistics, National Vital Statistics Reports, vol. 52, no. 10, Dec. 17, 2003. Web: www.cdc.gov/nchs .