Classically, the affected area of bowel assumes a spiral configuration and is described to have an "apple peel" like appearance; this is accompanied by lack of a dorsal mesentery (Type IIIb).

[citation needed] A third of infants with intestinal atresia are born prematurely[1] or with low birth weight.

These abnormalities are indications that the fetus may have a bowel obstruction which a more detailed ultrasound study can confirm.

[1] In type II, there is a gap in the bowel, and either end of the remaining intestine is closed off and connected to the other by a fibrous cord that runs along the edge of the mesentery.

[1] In type IIIb, also known as the "apple peel" or "Christmas tree" deformity, the atresia affects the jejunum, and the intestine is often malrotated with most of the mesenteric arteries absent.

The remaining ileum, which is of varying length, survives on a single mesenteric artery, which it is twisted around in a spiral form.

If the area affected is small, the surgeon may be able to remove the damaged portion and join the intestine back together.

In instances where the narrowing is longer, or the area is damaged and cannot be used for period of time, a temporary stoma may be placed.

[citation needed] The infant is usually given intravenous fluid hydration, and a nasogastric or orogastric tube may be used to aspirate the contents of the stomach.

The main factor in mortality is the availability of care and appropriate parenteral nutrition after surgery until the bowel can resume normal function.

[1] The most common complication is pseudo-obstruction at the site of surgery due to pre-existing intestinal dysmotility.

In 1889, English surgeon John Bland-Sutton proposed a classification system for intestinal atresia and suggested that it occurs at areas that are obliterated as part of normal development.

In 1900, Austrian physician Julius Tandler first put forward the theory that it may be caused by lack of recanalisation during development.

[2] The vascular ischemic cause of non-duodenal atresia was confirmed by Louw and Barnard in 1955 and was repeated in later studies.