Journal of Ultrasound in Medicine, Vol 6, Issue 1 3-6, Copyright © 1987 by American Institute of Ultrasound in Medicine
Fetal bowel. Normal sonographic findings
D. A. Nyberg, L. A. Mack, R. M. Patten and D. R. Cyr
The normal sonographic appearance of fetal colon and small bowel is
reported in a prospective study of 130 fetuses. The colon, which appeared
as a continuous tubular structure located around the perimeter of the
abdominal cavity, was seen in some fetuses as early as 22 menstrual weeks
and in all fetuses examined after 28 weeks. Colon diameter demonstrated a
linear relation (r = 0.82) with menstrual age, reaching a maximum of 18 mm
at term. In comparison, small bowel was located centrally and individual
segments never exceeded 7 mm in diameter or 15 mm in length. Small bowel
loops were seen in only 30% of fetuses examined after 34 weeks. Peristalsis
was routinely demonstrated of the small bowel, but was not observed in the
colon.