Fetal echogenic bowel
- Stephen T Chasen, MD
Stephen T Chasen, MD
- Professor of Clinical Obstetrics and Gynecology
- Weill Medical College of Cornell University
- Section Editors
- Louise Wilkins-Haug, MD, PhD
Louise Wilkins-Haug, MD, PhD
- Section Editor — Prenatal Diagnosis and Genetics
- Professor of Obstetrics, Gynecology, and Reproductive Biology
- Harvard Medical School
- Deborah Levine, MD
Deborah Levine, MD
- Section Editor — Imaging
- Professor of Radiology
- Director of Ob/Gyn Ultrasound
- Department of Radiology
- Beth Israel Deaconess Medical Center
The echogenicity of the fetal bowel is assessed during second trimester obstetrical ultrasound examination because increased echogenicity is a marker for several fetal disorders. However, most cases have no underlying abnormality and have normal outcomes.
DEFINITION AND DIAGNOSIS
Fetal echogenic bowel refers to increased echogenicity or brightness of the fetal bowel noted on second trimester sonographic examination (image 1A-B). Hyperechogenicity can be diffuse or focal, is uniform over a well-defined area that does not shadow, and is located primarily in the lower fetal abdomen and pelvis.
Various criteria for diagnosis of bowel echogenicity have been suggested. The simplest criteria, and the one that we use, is echogenicity similar to or greater than that of adjacent bone with the ultrasound gain set to the lowest point at which bone appears white . The iliac wing is the usual standard for comparison. Some authors have defined grades of echogenicity, with the most severe form (grade 3) being as bright as bone, while grades 1 and 2 are mildly or moderately echogenic .
Transducer frequency is important when considering the diagnosis of echogenic bowel. Higher frequency transducers can make the differentiation between normal and abnormal bowel echogenicity difficult, leading to over-diagnosis of the latter. As an example, a study using both 8 and 5 MHz transducers sequentially on the same fetuses found the frequency of echogenic bowel was 31 and 3 percent, respectively . For this reason, we only diagnose echogenic bowel when using a transducer frequency of 5 MHz or below. As discussed above, echogenicity similar to or greater than adjacent bone is a subjective determination, therefore prone to interobserver and intraobserver variability .
Differential diagnosis — Echogenic bowel should be distinguished from extra-intestinal echogenic masses and calcification in the fetal abdomen. The differential diagnosis includes gastric pseudo-mass, meconium peritonitis, and meconium "pseudocyst" (image 2A-B). A description of these and other less common echogenic lesions in the abdomen can be found separately. (See "Overview of echogenic masses and calcification in the fetal abdomen".)
- Al-Kouatly HB, Chasen ST, Streltzoff J, Chervenak FA. The clinical significance of fetal echogenic bowel. Am J Obstet Gynecol 2001; 185:1035.
- Nyberg DA, Dubinsky T, Resta RG, et al. Echogenic fetal bowel during the second trimester: clinical importance. Radiology 1993; 188:527.
- Vincoff NS, Callen PW, Smith-Bindman R, Goldstein RB. Effect of ultrasound transducer frequency on the appearance of the fetal bowel. J Ultrasound Med 1999; 18:799.
- Harrison KL, Martinez D, Mason G. The subjective assessment of echogenic fetal bowel. Ultrasound Obstet Gynecol 2000; 16:524.
- Sepulveda W, Sebire NJ. Fetal echogenic bowel: a complex scenario. Ultrasound Obstet Gynecol 2000; 16:510.
- Corteville JE, Gray DL, Langer JC. Bowel abnormalities in the fetus--correlation of prenatal ultrasonographic findings with outcome. Am J Obstet Gynecol 1996; 175:724.
- Goetzinger KR, Cahill AG, Macones GA, Odibo AO. Echogenic bowel on second-trimester ultrasonography: evaluating the risk of adverse pregnancy outcome. Obstet Gynecol 2011; 117:1341.
- Mailath-Pokorny M, Klein K, Klebermass-Schrehof K, et al. Are fetuses with isolated echogenic bowel at higher risk for an adverse pregnancy outcome? Experiences from a tertiary referral center. Prenat Diagn 2012; 32:1295.
- Simon-Bouy B, Satre V, Ferec C, et al. Hyperechogenic fetal bowel: a large French collaborative study of 682 cases. Am J Med Genet A 2003; 121A:209.
- Petrikovsky B, Smith-Levitin M, Holsten N. Intra-amniotic bleeding and fetal echogenic bowel. Obstet Gynecol 1999; 93:684.
- Sepulveda W, Reid R, Nicolaidis P, et al. Second-trimester echogenic bowel and intraamniotic bleeding: association between fetal bowel echogenicity and amniotic fluid spectrophotometry at 410 nm. Am J Obstet Gynecol 1996; 174:839.
- Berger S, Ziebell P, OFFsler M, Hofmann-von Kap-herr S. Congenital malformations and perinatal morbidity associated with intestinal neuronal dysplasia. Pediatr Surg Int 1998; 13:474.
- Carcopino X, Chaumoitre K, Shojai R, et al. Foetal magnetic resonance imaging and echogenic bowel. Prenat Diagn 2007; 27:272.
- Bromley B, Doubilet P, Frigoletto FD Jr, et al. Is fetal hyperechoic bowel on second-trimester sonogram an indication for amniocentesis? Obstet Gynecol 1994; 83:647.
- Irish MS, Ragi JM, Karamanoukian H, et al. Prenatal diagnosis of the fetus with cystic fibrosis and meconium ileus. Pediatr Surg Int 1997; 12:434.
- Muller F, Dommergues M, Simon-Bouy B, et al. Cystic fibrosis screening: a fetus with hyperechogenic bowel may be the index case. J Med Genet 1998; 35:657.
- Scotet V, Duguépéroux I, Audrézet MP, et al. Focus on cystic fibrosis and other disorders evidenced in fetuses with sonographic finding of echogenic bowel: 16-year report from Brittany, France. Am J Obstet Gynecol 2010; 203:592.e1.
- Fox NS, Huang M, Chasen ST. Second-trimester fetal growth and the risk of poor obstetric and neonatal outcomes. Ultrasound Obstet Gynecol 2008; 32:61.
- Al-Kouatly HB, Chasen ST, Karam AK, et al. Factors associated with fetal demise in fetal echogenic bowel. Am J Obstet Gynecol 2001; 185:1039.
- Salafia CM, Silberman L, Herrera NE, Mahoney MJ. Placental pathology at term associated with elevated midtrimester maternal serum alpha-fetoprotein concentration. Am J Obstet Gynecol 1988; 158:1064.
- Achiron R, Seidman DS, Horowitz A, et al. Hyperechogenic fetal bowel and elevated serum alpha-fetoprotein: a poor fetal prognosis. Obstet Gynecol 1996; 88:368.
- Strocker AM, Snijders RJ, Carlson DE, et al. Fetal echogenic bowel: parameters to be considered in differential diagnosis. Ultrasound Obstet Gynecol 2000; 16:519.
- Slotnick RN, Abuhamad AZ. Prognostic implications of fetal echogenic bowel. Lancet 1996; 347:85.
- Dicke JM, Crane JP. Sonographically detected hyperechoic fetal bowel: significance and implications for pregnancy management. Obstet Gynecol 1992; 80:778.
- Ghose I, Mason GC, Martinez D, et al. Hyperechogenic fetal bowel: a prospective analysis of sixty consecutive cases. BJOG 2000; 107:426.
- Bashiri A, Burstein E, Hershkowitz R, et al. Fetal echogenic bowel at 17 weeks' gestational age as the early and only sign of a very long segment of Hirschsprung disease. J Ultrasound Med 2008; 27:1125.
- Lam YH, Tang MH, Lee CP, Tse HY. Echogenic bowel in fetuses with homozygous alpha-thalassemia-1 in the first and second trimesters. Ultrasound Obstet Gynecol 1999; 14:180.
- Hill M, Twiss P, Verhoef TI, et al. Non-invasive prenatal diagnosis for cystic fibrosis: detection of paternal mutations, exploration of patient preferences and cost analysis. Prenat Diagn 2015; 35:950.
- Saha E, Mullins EW, Paramasivam G, et al. Perinatal outcomes of fetal echogenic bowel. Prenat Diagn 2012; 32:758.
- Patel Y, Boyd PA, Chamberlain P, Lakhoo K. Follow-up of children with isolated fetal echogenic bowel with particular reference to bowel-related symptoms. Prenat Diagn 2004; 24:35.