Question: Which are the main causes of fetal echogenic bowel?

Context:
In group 2 and 3, two anomalies, anorectal malformation and cystic fibrosis, were detected postnatally
Six had chromosomal/genetic abnormalities, two had congenital cytomegalovirus, none had cystic fibrosis
Primary bowel pathology is rare following the finding of FEB
Maternal serology for cytomegalovirus (CMV) was performed in 49 (78%) cases
Thirty-three pregnancies (53%) were tested for cystic fibrosis (CF) and 1 baby was confirmed to have CF postnatally
This study reiterates the increased prevalence of aneuploidy, CMV, CF and fetal growth restriction in pregnancies complicated by the midtrimester sonographic finding of FEB
Primary outcomes were IUGR, defined as birth weight less than the 10th percentile for gestational age and intrauterine fetal demise at 20 weeks or more of gestatio
Analyses were repeated after excluding cases of aneuploidy, cytomegalovirus (CMV) infection,
The presence of echogenic bowel on ultrasonography is independently associated with an increased risk for both IUGR and intrauterine fetal demise
This study highlights the importance of pregnancy ultrasound examinations and their efficiency in detecting cystic fibrosis
A disorder was diagnosed in 32.2% of the fetuses, cystic fibrosis being the most commonly identified (7.6%). We also found digestive malformations (7.0%), chromosomal abnormalities (3.7%), and maternofetal infections (3.7%).
A potential association with placental abnormalities and a low prevalence of viral infections was observed
Our data suggests an inverse relationship between the maternal BMI and the detection of fetal EIF and/or EB
Fetal echogenic bowel at 17 weeks' gestational age as the early and only sign of a very long segment of Hirschsprung disease.
fetal ultrasound findings associated with intrauterine cytomegalovirus (CMV) infection
the combination of hydrops fetalis, cerebral hemorrhage, and hyperechoic bowel should raise the possibility of a CMV infection
strongly associated with adverse pregnancy outcome due to utero-placental insufficiency, particularly in women with elevated maternal serum alpha-fetoprotein concentration due to severe feto-maternal bleeding
Congenital cytomegalovirus infection presenting with echogenic bowel and oligohydramnios.
Five cases of trisomy 21 and one case of trisomy 18 were detected
Brightly echogenic bowel in the second trimester was found to be associated with a significant risk of fetal aneuploidy.
echogenic bowel does not uniformly herald an abnormal outcome. Echogenic bowel coexistent with other abnormalities (such as growth deficiency or structural malformations) may be a comarker for aneuploidy.
Congenital cytomegalovirus infection with oligohydramnios and echogenic bowel at 14 weeks' gestation
Parental CF carrier testing and amniocentesis to identify aneuploidy or fetal CF status has a high positive ascertainment rate in fetuses with echogenic bowel grades 2 and 3.
Swallowing of amniotic fluid after intraamniotic bleeding seems implicated in the etiology of second-trimester echogenic bowel in both euploid and aneuploid fetuses
Fetal echogenic bowel and a dilated loop of bowel associated with cystic fibrosis (CF) mutations delta F508 and 2183AA-->G
Fifteen cases (19%) were associated with maternal vaginal bleeding
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%).
Fetal echogenic bowel has been reported as a normal variant in the second trimester, and has also been associated with an adverse fetal outcome, including cystic fibrosis (CF)
Intra-amniotic bleeding can lead to echogenic bowel
112 cases (57%) had a known etiology, which included chromosomal abnormality (7%), infection (4%), cystic fibrosis (1.5%), bowel abnormality (3%), bleeding or stained amniotic fluid (11%), Doppler abnormality (14%), malformation (16%) and miscellaneous (0.5%)

Answer: Fetal echogenic bowel is mainly associated to feto-maternal, intramniotic bleeding but in several cases it is linked to cystic fibrosis, cytomegalovirus (CMV), herpes simplex virus and other viral infections and fetal aneuploidy.
Fetal echogenic bowel (FEB) is a soft marker found on second trimester sonography. (PMID: 22990134) A disorder was diagnosed in 32.2% of the fetuses, cystic fibrosis being the most commonly identified (7.6%). We also found digestive malformations (7.0%), chromosomal abnormalities (3.7%), and maternofetal infections (3.7%). (PMID: 20932506) Brightly echogenic bowel in the second trimester was found to be associated with a significant risk of fetal aneuploidy. (PMID: 1415421) echogenic bowel does not uniformly herald an abnormal outcome. Echogenic bowel coexistent with other abnormalities (such as growth deficiency or structural malformations) may be a comarker for aneuploidy. (PMID: 8142051) 112 cases (57%) had a known etiology, which included chromosomal abnormality (7%), infection (4%), cystic fibrosis (1.5%), bowel abnormality (3%), bleeding or stained amniotic fluid (11%), Doppler abnormality (14%), malformation (16%) and miscellaneous (0.5%) (PMID: 12835583)
Exact answer: Itramniotic bleeding
CMV infection
Cystic Fibrosis (CF)
Fetal aneuploidy