Handbook of 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 and to monitor growth
 * all women with this ultrasound finding should be counselled and their risk factors assessed to determine whether they should undergo an amniocentesis for 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