Echogenic bowel in the second trimester - Where to from here?

Echogenic bowel is a 'soft marker' on prenatal ultrasound, which can be associated with a variety of conditions including chromosomal disorders, intrapartum infections, antepartum events and cystic fibrosis. Identification of this marker should prompt a further search for other soft markers, structural defects and placental abnormalities. We explore three cases of echogenic bowel identified on routine ultrasound scan. The first case highlights the potential for echogenic bowel to be a benign feature. Echogenic bowel was identified at eighteen weeks, which was attributed to intra-amniotic haemorrhage and consequent fetal ingestion of blood products. In contrast, the next two cases highlight the pathological causes of echogenic bowel. In case 2, echogenic bowel was identified at seventeen weeks with associated cystic hygromas. The fetus had positive testing for Turner syndrome, and notably, there was a family history of cystic fibrosis. The third case discusses a case of congenital cytomegalovirus infection, which was diagnosed with amniocentesis and maternal serology testing when echogenic bowel was identified. A review of the literature suggests that the risk of adverse outcomes is increased with the presence of multiple soft markers, associated deformities, poor growth, persistent echogenic bowel in the third trimester and increased echogenic resolution. Despite these factors, it is important to note the poor ultrasonographic sensitivity of less than 50% in neonates with congenital cytomegalovirus infection and the consequent importance of invasive testing. Therefore, we aim to propose an action plan for clinicians who identify echogenic bowel on prenatal scans in order to critically exclude detrimental pathology.