Preterm refers to a baby that is born before the 37th week of gestation. Synonyms for this term include premature, early, preemie, prelabor, and premature-born. Premature is perhaps the most common synonym, and it can refer to anything that happens before an expected or usual time, not just a baby's birth status. Preemie and prelabor are more specific, referring directly to a baby born too early and the period of labor before the due date, respectively. Finally, premature-born is also a simple way to describe a baby who is born too early and can be especially useful when discussing medical histories.