These days, it seems babies are getting smaller and smaller. Because so many infants are born so small, they would not have survived before today’s modern neonatal intensive care units (NICU). Being small for gestational age (SGA) is a major public health problem and prevention is a major public health goal. Simply put, very small babies are less likely to survive than larger babies. The definition of SGA takes into account the babies born early who tend to weigh less.