What gestational age classification does SGA relate to?

Small for gestational age (SGA) refers to infants whose birth weight is below the 10th percentile for their gestational age. This classification can apply across various gestational ages, including preterm, term, and postterm infants.

Infants may be SGA at any point in gestation, indicating that they have not achieved adequate growth relative to their peers at the same gestational age. For instance, a preterm baby born before 37 weeks of gestation can be SGA if their weight is less than expected for that gestational age. Similarly, a term baby (born between 37 to 42 weeks) and even a postterm baby (born after 42 weeks) can also be classified as SGA if their weight does not meet the percentile criteria.

This classification highlights that SGA is not limited to a single category but rather spans all gestational ages, illustrating the critical importance of monitoring fetal growth throughout pregnancy to identify any growth restrictions that may be present at various points in gestation.