Definitions for Gestational Age and Birth Weight
Term
- Term: birth between 37 and 42 weeks
- Pre-term: birth prior to 37 completed weeks of gestation
- Post-term: birth after 42 weeks of gestation
Gestational age
Gestational age can be calculated by the date of the last menstrual period and also by examination of the newborn infant using the Dubowitz or Ballard score. The Ballard score is an abbreviated version of the Dubowitz score, especially useful for estimation of gestational age in premature babies.
- Appropriate for gestational age (AGA): the baby's weight is appropriate for the gestational age (weight between 10th and 90th percentile)
- Small for gestational age (SGA): a baby's weight is less than expected for the gestational age (weight less than 10th percentile). Unlike a preterm baby, an SGA baby is small because of slow growth resulting from an inherent fetal growth retardation.
- Large for gestational age (LGA): a baby's weight is more than expected for the gestational age (weight more than the 90th percentile).
More Info: Ballard Score from Medcalc
