Evaluation of fetal echogenic bowel in the second trimester

Previous studies cite different possible etiologies for fetal echogenic bow el (FEB). The purpose of this study was to evaluate the possible etiologies for second-trimester FEB, and to provide clinical guidelines for evaluatio n of this finding. The study included 79 patients diagnosed with FEB in the second trimester. Fifteen cases (19%) were associated with maternal vagina l bleeding. Of these, 12 patients underwent amniocentesis, 9 of which had v isible blood products in the amniotic fluid. Seven cases (8.9%) had associa ted severe malformation. Seven other cases (8.9%) were noted in multifetal pregnancies. Five fetuses (6.3%) had evidence of bower obstruction or perfo ration not associated with cystic fibrosis (CF). Chromosomal aberrations we re found in 5 fetuses (6.3%). Intrauterine infection with cytomegalovirus, herpes simplex virus, varicella-zoster virus, or parvovirus B-19 was docume nted in 5 patients (6.3%). Three cases (3.8%) were associated with subseque nt unexplained stillbirth. Two fetuses (2.5%) were found to be affected by CF. Finally, in 30 cases (38%), no obvious rea son for FEB was found. We co nclude that the evaluation of second-trimester FEB should include targeted ultrasound for associated malformations, infectious studies, DNA analysis f or CF mutations, amniocentesis for chromosomal analysis and evaluation of t he amniotic fluid for degraded blood products, and an autopsy in cases of s tillbirth. Even when no apparent reason is found, pregnancies should be con sidered at high risk for poor outcome.