OBJECTIVE: The purpose of this study was to determine the incidence of cystic 
fibrosis, aneuploidy, and intrauterine infection with toxoplasmosis and 
cytomegalovirus in second-trimester fetuses with the sonographic finding of 
echogenic bowel.
STUDY DESIGN: All cases of echogenic bowel that were diagnosed in our ultrasound 
unit from 1993 to 2000 were identified. Only cases in which bowel echogenicity 
was as bright as bone with no associated major fetal anomalies were included. 
Patients who were referred from other hospitals were excluded. Echogenicity was 
classified as focal or multifocal. Fetal karyotypes, cystic fibrosis carrier 
testing, and maternal serologic test results were determined.
RESULTS: One hundred seventy-five fetuses in 171 pregnancies met inclusion 
criteria. Cystic fibrosis mutations were identified in 7 of 138 mothers (5%) and 
9 of 86 fathers (10.5%) who were tested. Five fetuses were affected with cystic 
fibrosis. Fetal karyotype was obtained in 139 cases, and autosomal trisomy was 
diagnosed in 5 cases (3.6%). One hundred sixty-six patients were tested for 
toxoplasmosis, and 111 patients were tested for cytomegalovirus. There were no 
cases of congenital toxoplasmosis. There was maternal serologic and fetal 
pathologic evidence of cytomegalovirus infection in 1 case. In all cases of 
cystic fibrosis and aneuploidy, echogenicity was multifocal; in the case of 
cytomegalovirus, echogenicity was focal.
CONCLUSION: In our population, mid-trimester fetal echogenic bowel was 
associated with a high prevalence of cystic fibrosis, aneuploidy, and 
cytomegalovirus (11/175 fetuses [6.3%]). This information should be considered 
when counseling patients after mid-trimester echogenic bowel is diagnosed.