Evaluation of Fetal Echogenic Bowel in the Second Trimester

Abstract

Previous studies cite different possible etiologies for fetal echogenic bowel (FEB). The purpose of this study was to evaluate the possible etiologies for second-trimester FEB, and to provide clinical guidelines for evaluation of this finding. The study included 79 patients diagnosed with FEB in the second trimester. Fifteen cases (19%) were associated with maternal vaginal bleeding. Of these, 12 patients underwent amniocentesis, 9 of which had visible blood products in the amniotic fluid. Seven cases (8.9%) had associated severe malformation. Seven other cases (8.9%) were noted in multifetal pregnancies. Five fetuses (6.3%) had evidence of bowel obstruction or perforation not associated with cystic fibrosis (CF). Chromosomal aberrations were found in 5 fetuses (6.3%). Intrauterine infection with cytomegalovirus, herpes simplex virus, varicella-zoster virus, or parvovirus B-19 was documented in 5 patients (6.3%). Three cases (3.8%) were associated with subsequent unexplained stillbirth. Two fetuses (2.5%) were found to be affected by CF. Finally, in 30 cases (38%), no obvious reason for FEB was found. We conclude that the evaluation of second-trimester FEB should include targeted ultrasound for associated malformations, infectious studies, DNA analysis for CF mutations, amniocentesis for chromosomal analysis and evaluation of the amniotic fluid for degraded blood products, and an autopsy in cases of stillbirth. Even when no apparent reason is found, pregnancies should be considered at high risk for poor outcome.

Second trimester ultrasonographic diagnosis of ileal atresia, histopathological findings consistent with cystic fibrosis and negative genetic tests

“…Therefore, when considering differential diagnosis for fetal echogenic bowel it is necessary to scan for other markers of aneuploidy, assessment of growth, screen for infections and assess the risk status for cystic fibrosis as well as structural malformations, especially gastrointestinal [1,7,8]. Moreover, Yuval et.…”

“…al. [8] least one possible explanation is the access of blood or blood products to the amniotic fluid. The echogenicity in these cases is most likely secondary to ingested blood in the fetal gastrointestinal tract.…”

Genetic Screening for Aneuploidy in the Second-trimester

“…Different pathological conditions such as trisomy 21, cystic fibrosis, severe early onset of IUGR, thalassemia, intramniotic bleeding, gastrointestinal obstruction, mesenteric ischemic, perinatal death and cytomegalovirus infections have been associated with second trimester hyperchoid bowel. [25][26][27] Poor perinatal outcome has been noted in 1/3 of pregnancies with FEB including chromosomal defect in 9% of the cases, cystic fibrosis in 2%, congenital infection in 3% and IUGR in 8%.…”

Etiology and Outcome of Fetal Echogenic Bowel

“…DNA analysis is used to screen for CF mutations. The mutation panel is currently expanded in many coun-tries and includes up to 32 mutations in certain centers [1,3]. A normal test does not completely exclude CF, as rare or unknown mutations may be present, thus making a postnatal sweat test necessary [9,11].…”

“…Denholm et al [2] first reported a relation to cystic fibrosis (CF) in 1984. Once considered a normal variant, FEB has since been linked to many diseases including CF, aneuploidy, congenital infection, fetal abnormalities, gastrointestinal obstruction or perforation, intra-amniotic bleeding, in utero growth retardation (IUGR), intrauterine fetal death (IUFD) and fetal alcohol syndrome [3][4][5][6]. The purpose of this study was to analyze diagnostic findings in FEB and the corresponding outcome of pregnancy in order to identify indicators of high-risk situations.…”