Fetal echogenic bowel has been reported as a normal variant in the second 
trimester, and has also been associated with an adverse fetal outcome, including 
cystic fibrosis (CF), an autosomal recessive genetic disease. Previous studies 
have reported that 3.3 to 13.3 per cent of fetuses with echogenic bowel 
discovered during the second trimester were affected with CF. Between 1994 and 
1998 our laboratory tested 159 cases with echogenic bowel detected during a 
routine ultrasound examination. The ethnic/racial background of cases included 
Caucasian, African-American, Middle Eastern, Hispanic, Ashkenazi Jewish and 
Asian. We identified two CF fetuses (1.3 per cent) and eight fetuses with a 
single identifiable CF mutation (5 per cent) within this diverse population. 
These data indicated that the risk of CF in a fetus with echogenic bowel in this 
population was less than the 3.3 to 13.3 per cent prior risk currently used in 
most Bayesian calculations. Furthermore, the results suggested that specific 
risks for couples should be calculated using data specific for their ethnic or 
racial background. Based on our results, we recommend either amniocentesis for 
fetal CF studies or CF carrier screening of both parents when fetal echogenic 
bowel is detected as a 1.3 per cent risk of CF is considered high enough to 
warrant further testing.