Influence of Antenatal Ultrasound on the Management of Fetal Exomphalos

Abstract

Objective: To determine the influence of antenatal ultrasound on the management of exomphalos. Methods: Retrospective case note review of 23 fetuses and infants referred to our institution with either a pre- or postnatal diagnosis of exomphalos over a 7-year period. Results: There were 21 cases of exomphalos of which 18 were correctly diagnosed on antenatal ultrasound by 18 weeks’ gestation. There were 2 false-positives and 3 false-negatives, including 1 case of amniotic band syndrome with an abdominal wall defect and 1 morphologically normal fetus. Associated anomalies were correctly identified in 12 but incorrectly reported in 8. Maternal serum α-fetoprotein levels were abnormal in 61% of cases of abdominal wall defects in this series. Amniocentesis was performed in 12 and cordocentesis in 1. There were 13 terminations, including 2 trisomy 18s and 1 trisomy 13. Two fetal deaths followed amniocentesis. Of the 10 live births, 9 had their exomphalos repaired with a 1-year survival rate of 89%. Prenatal diagnosis did not appear to influence outcome. Conclusions: Antenatal ultrasound diagnosed 86% of cases of exomphalos and correctly reported 67% of associated anomalies. Amniocentesis may have led to the death of 1 morphologically normal fetus.

Spontaneous intraamniotic hemorrhage in the second trimester mimicking an abdominal wall defect

“…There are some case reports which falsely presumed the presence of omphalocele in association with oligohydramnios (11)(12)(13). Diastatic and lax foetal abdominal wall with protrusion of the liver and other organs, abnormal foetal positioning with a decreased amount of amniotic fluid and failure to identify the umbilical cord have all been considered the cause (11)(12)(13). These cases are comparable to our case because the relatively small amount of amniotic fluid and compression of the abdominal wall may have caused a false positive diagnosis.…”

“…Walkinshaw et al (9) described a false-positive rate of 5.3% during the mid1980s and recently a false-positive rate of 2% was reported by Kleinrouweler et al (10). There are some case reports which falsely presumed the presence of omphalocele in association with oligohydramnios (11)(12)(13). Diastatic and lax foetal abdominal wall with protrusion of the liver and other organs, abnormal foetal positioning with a decreased amount of amniotic fluid and failure to identify the umbilical cord have all been considered the cause (11)(12)(13).…”

Unusual fetal abdominal wall presentation mimicking an abdominal wall defect

“…5 In the second case an exomphalos with an extracorporeal liver was associated with echogenic kidneys and oligohydramnios. 6 In both cases, however, no abdominal wall defect was diagnosed after delivery. These cases are comparable to our case because of the relatively little amount of amniotic fluid and compression of the abdominal wall resulting in images mimicking an abdominal wall defect.…”

Congenital Abdominal Wall Defects: An Update

“…Polyhydramnios may be associated with omphalocele. Additional investigations should include amniocentesis [84,85,92,113] (chromosomal, ·-fetoprotein and molecular analysis), fetal echocardiography [84,91] and MRI [114]. Prenatal testing is offered by chromosome analysis for families with an inherited chromosome abnormality or by molecular genetic testing for families with a defined molecular mechanism [92].…”