Genetic counseling: Echogenic Bowel

Echogenic Bowel

What is it?

 * when, on ultrasound, the fetus' bowel appears to have more echogenicity than the liver, or similar or greater echogenicity than the surrounding bone
 * can be a transient feature

What does it mean?

 * most likely etiology is intra-amniotic bleeding and swallowing of the stained fluid by the fetus, followed by its accumulation within the meconium
 * can be indicative of a chromosome abnormality (e.g., Down Syndrome, Cystic Fibrosis)
 * is most often a non-specific finding (seen in fetuses with intestinal obstruction/blockage, congenital cytomegalovirus infection, growth restriction)
 * has been reported as a normal variant during the second trimester
 * can also be indicative of early ascites, fetal hypoxia, placental insufficiency, and meconium peritonitis

What are the risks?

 * the risk of Down Syndrome in fetuses with isolated hyperechogenic bowel is 1.4%
 * in "high risk" women (abnormal MSAFP screen, family history of Cystic Fibrosis, and/or AMA), echogenic bowel is associated with:
 * Cystic Fibrosis in 3% of fetuses
 * chromosome abnormalities in 12.4% of fetuses
 * (most data has been collected from this high risk group)
 * 12.5% of fetuses with Down Syndrome have been reported to have echogenic bowel
 * the only abnormal ultrasound finding in 41% of these cases
 * chromosomal abnormalities are more often diagnosed when there are findings in addition to hyperechogenic bowel (multiple abnormalities)

What should be done?

 * future ultrasounds should be performed to determine if the finding is transient
 * all women with this ultrasound finding should undergo a fetal karyotype, parental CF mutation studies, and assessment of the presence of a congenital infection

Reference

 * Genetic Disorders and the Fetus. 4th Edition Ed. Aubrey Milunsky. 1998