Early sonographic detection of fetal intestinal obstruction and possible diagnostic pitfalls.

We present five fetuses at 15-17 weeks' gestation with a sonographic diagnosis of intestinal obstruction. Dilation of the intestine was the presenting sonographic finding in fetuses with a volvulus and/or anal atresia. Two of the fetuses also had other abnormalities. Intestinal peristalsis may be observed in early pregnancy as transient dilation of intestinal segments. Sonographers are cautioned about a false-positive diagnosis of intestinal obstruction in such cases.