Symmetrical Vs. Asymmetrical
There are 2 major categories of IUGR: symmetrical and asymmetrical.
Asymmetrical IUGR is more common. In asymmetrical IUGR, there is restriction of weight followed by length. The head continues to grow at normal or near-normal rates (head sparing). This is a protective mechanism that may have evolved to promote brain development. This type of IUGR is most commonly caused by extrinsic factors that affect the fetus at later gestational ages.
Symmetrical IUGR is less common and is more worrisome. This type of IUGR usually begins early in gestation. Since most neurons are developed by the 18th week of gestation, the fetus with symmetrical IUGR is more likely to have permanent neurological sequela.
Read more about this topic: Intrauterine Growth Restriction
Famous quotes containing the word symmetrical:
“In nature, all is useful, all is beautiful. It is therefore beautiful, because it is alive, moving, reproductive; it is therefore useful, because it is symmetrical and fair. Beauty will not come at the call of a legislature, nor will it repeat in England or America its history in Greece. It will come, as always, unannounced, and spring up between the feet of brave and earnest men.”
—Ralph Waldo Emerson (1803–1882)