Objective-To estimate if echogenic bowel diagnosed on second-trimester ultrasound has an independent risk association with intrauterine growth restriction (IUGR) and intrauterine fetal demise.Methods-This is a retrospective cohort study of all patients with singleton gestations who presented to our institution for second-trimester ultrasound between 1990 and 2008. Study groups were defined by the presence or absence of echogenic bowel. Primary outcomes were IUGR, defined as birth weight less than the 10 th percentile, and intrauterine fetal demise at 20 weeks or more of gestation. Univariable and multivariable logistic regression analyses were used to estimate the risk of intrauterine fetal demise and IUGR in fetuses with echogenic bowel. Analyses were repeated after excluding cases of aneuploidy, cytomegalovirus (CMV) infection, other major congenital anomalies, and abnormal second-trimester serum screening results.Results-Of 64,048 patients, the incidence of echogenic bowel was 0.4%. Of these, echogenic bowel was an isolated finding in 188 (72.3%) cases. There were 579 (0.9%) cases of intrauterine fetal demise and 8,173 (12.8%) cases of IUGR in the entire cohort. After excluding cases of aneuploidy and CMV infection, the incidence of IUFD was 7.3% in the echogenic bowel group compared to 0.9% in the non-echogenic bowel group, translating to an absolute risk increase (ARI) of 6.4%. The incidence of IUGR in the echogenic bowel group was 19.5% compared to 12.9% in the non-echogenic bowel group (ARI=6.6%). After controlling for potential confounders, echogenic bowel was signficantly associated with both IUFD (aOR 9.6, 95% CI 5.8-15.9) and IUGR (aOR 2.1, 95% CI 1.5-2.9) This risk association remained significant even when evaluating echogenic bowel as an isolated sonographic finding.
Conclusion-The presence of echogenic bowel on ultrasound is independently associated with an increased risk for both IUGR and IUFD. Serial growth assessment and antenatal testing may be warranted in these patients.