prematurity为什么要写早熟？

Morbidity and mortality track much more closely with GA compared to BW. This is thought to be based on the organ prematurity associated with low GA, that may not be found to the same degree in term infants that may have isolated intrauterine growth restriction (IUGR) and resultant low birth weight [1].

是这么理解吗，早产儿器官成熟比宫内生长受限的要差一些

与出生体重（BW）相比，孕龄(GA)与发病率和死亡率关系更密切。这被认为是基于与低GA相关的器官早熟，这在宫内生长受限(intrauterine growth restriction，IUGR)和由此导致的低出生体重的足月儿中并没有如此严重[1]。

prematurity为什么要写早熟？应该是不成熟才对，早熟了就成熟了