Historically, neonates born below the 10th percentile in birth weight for their gestational age have been labelled small for gestational age, often abbreviated as SGA. Most physicians further characterized these neonates as having symmetric or asymmetric growth restriction; asymmetric was often referred to as intrauterine growth restriction (IUGR).
Prior to adoption of International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), ICD-9-CM referred to both as “light for dates,” with a further characterization as with or without signs of fetal malnutrition. On the other extreme, neonates with birth weight greater than the 90th percentile have been referred to as large for gestational age (LGA).
ICD-10-CM changed the terminology slightly, replacing “for dates” with “for gestational age.” Furthermore, ICD-10-CM clearly differentiates symmetric from asymmetric growth restriction. However, the terminology has been somewhat confusing.
Note that head circumference is not part of the definition.
Coding for services to a neonate...