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Chapter 38 ■ The Fetal Abdominal Wall and Gastrointestinal Tract 1337
EB
Stomach with
debris
A B
FIGURE 38-14. Echogenic bowel. A, Echogenic bowel (arrow EB) in a fetus with previously seen subchorionic hemorrhage. Note
small amount of debris in stomach. B, Echogenic bowel (arrows) in fetus with cytomegalovirus infection.
ECHOGENIC BOWEL: COMMON
ASSOCIATED RISKS
Aneuploidy
Cystic fibrosis
Swallowed fetal blood
Infection
Gastrointestinal atresias
Intrauterine growth restriction
Fetal demise
increases throughout pregnancy, the finding of echogenic bowel becomes normal in the third trimester. In
particular, meconium in the colon can be seen normally
as echogenic material in the third trimester.
Echogenic bowel is associated with numerous etiologies. In most cases the lumen of the bowel itself is later
found to be normal. However, the in utero diagnosis is
associated with fetal and placental abnormalities and an
increased risk of poor pregnancy outcome, even when
the second-trimester evaluation is otherwise normal.
Because of these implications, an experienced sonographer must carefully evaluate the fetus and placenta
and offer counseling and follow-up. In most fetuses
with echogenic bowel in the second trimester, the bowel
findings become normal as the pregnancy progresses.
However, this should not eliminate the possibility of
an abnormal pregnancy, because many of the associated
complications do not occur until the third trimester.
Aneuploidy
The confirmation of hyperechoic bowel on second-trimester ultrasound requires careful evaluation of the fetus
because of the association with chromosomal abnormalities. The most common abnormal karyotype is trisomy
21, but trisomies 13 and 18, 45,X, and triploidies have
all been reported in fetuses with echogenic bowel.
109-113
In all series, fetuses with chromosomal abnormalities are
likely to have other abnormal sonographic findings. The
risk of aneuploidy in fetuses with echogenic bowel as an
isolated finding is 1.4% to 5%.
ciated with GI dysfunction and dysmotility.
109-113
Trisomy 21 is asso-
114
Thus, it
is hypothesized that the dysmotility is the pathophysiologic cause of the echogenicity in aneuploid fetuses.
However, most fetuses with trisomy 21 and echogenic
bowel show no GI complication postnatally.
50
Cystic Fibrosis
Echogenic bowel, meconium cysts, and peritonitis are
the sonographic findings visible in the second trimester
in fetuses with CF. With confirmed diagnosis of CF, the
echogenic appearance of the bowel is caused by the biochemical alterations in the secretory-digestive-absorptive
function of the small intestinal mucosa, leading to meconium obstruction in small bowel, primarily meconium
115
ileus.
echogenic bowel varies from 1.3% to 5%.
The incidence of CF in fetuses with isolated
108,116,117
Swallowed Fetal Blood
Echogenic bowel has been noted in pregnancies complicated by vaginal bleeding, in those with asymptomatic
subchorionic hemorrhage, and with the unexpected
finding of new or old blood on amniocentesis performed
for chromosomal analysis. In some fetuses with known
second-trimester bleeding, the swallowed blood is visible
in the fetal stomach on ultrasound, along with the hyperechoic bowel. In these fetuses it was concluded that the
increased density of the swallowed blood causes the
increased echogenicity. In a case series of pregnancies
with isolated echogenic bowel undergoing amniocentesis, even pregnancies without evidence of bleeding
and with normal-appearing amniotic fluid had evidence
1338 PART IV ■ Obstetric Sonography
of blood in the fluid on spectrophotometry.50 In one
series, 19% of fetuses with isolated echogenic bowel had
sonographic findings of intrauterine bleeding, of which
70% were confirmed to have intra-amniotic bleeding on
amniocentesis.
118
Fetal Viral Infection
Fetal viral infections including cytomegalovirus (CMV)
and parvovirus infection are other associated etiologies
of echogenic bowel. The range in incidence of viral
infections in fetuses with echogenic bowel is 0.5% to
118-120
6.3%.
The etiology of the echogenic bowel in
fetuses with viral infection is not known.
Later Diagnosis of
Gastrointestinal Atresias
As previously noted, fetuses with trisomy 21 or CF and
those with normal chromosomes and negative for CF
have echogenic bowel as a second-trimester finding of a
later-diagnosed GI atresia (see Fig. 38-11).
Intrauterine Growth Restriction
and Fetal Demise
MECONIUM PERITONITIS: NEED FOR
POSTNATAL SURGERY (%)
Isolated calcifications: 0%
Calcifications and pseudocyst, ascites, or bowel
dilation: 52%
Calcifications and two of pseudocyst, ascites, or
bowel dilation: 80%
Calcifications, pseudocyst, ascites, and bowel
dilation: 100%
Polyhydramnios and any of above findings: 69%
this is termed a meconium pseudocyst (Figs. 38-15, C,
and 38-16). Associated ultrasound findings include
ascites, polyhydramnios, and dilated bowel.
meconium ileus and meconium peritonitis are associated
with CF in 8% to 40% of cases.
tonitis has been classified to predict a postnatal surgical
requirement.
127
The risk of need for postnatal surgery
124,126
124,125
Both
Meconium peri-
increases with the number of findings. Once meconium
peritonitis or ileus has been diagnosed, serial fetal sonography in recommended. Because of the association with
postnatally diagnosed fetal anomalies, delivery at a center
with a neonatal intensive care unit (NICU) and pediatric
surgery is suggested.
The risk of both intrauterine growth restriction (IUGR)
and fetal demise increases in the second and third trimesters after the second-trimester diagnosis of echogenic
bowel. Incidence is 10% for IUGR
for fetal demise.
116,121,122
Subchorionic hematoma is
associated with IUGR and fetal demise,
116
and 5.8% to 15%
123
and in some
pregnancies, echogenic bowel may be the only clinical
evidence of abnormal placentation, which could explain
some of the poor outcomes in these fetuses.
Summary
Because of the association of echogenic bowel with fetal
abnormalities, the following are recommended when
echogenic bowel is identified in the second trimester:
genetic counseling, consideration of karyotype, evaluation for fetal viral infection, and CF testing. In addition,
regardless of whether the patient chooses amniocentesis,
serial fetal growth ultrasound and antenatal testing
should be done later in pregnancy.
MECONIUM PERITONITIS
AND PSEUDOCYST
ENTERIC DUPLICATION CYST
Duplication cysts of the enteric tract are classified by the
region of associated bowel, not by the histology of the
mucosal lining.
10,000 infants.
ciated with any area of the alimentary tract and can
present in utero or postnatally as obstructions.
ciated anomalies occur in 30% of cases, most often gastrointestinal.
Gastric duplication cysts present at ultrasound as
cystic or echogenic tubular structures with defined
borders. They are classically anechoic and cystic, but
at times are filled with echogenic material. The borders
typically have double lumens
38-2). Depending on the site of presentation, the differential diagnosis includes hepatic or choledochal cysts,
bowel atresias, and ovarian cysts. Peristalsis of the cysts
has been reported and can differentiate these masses
from those of non-GI origin.
treatment is surgical, because of the association with
delayed obstructions.
128
The incidence is estimated at 1 per
129
Enteric duplication cysts may be asso-
129,130
130
The majority of duplications are ileal.
130
(Fig. 38-17; Video
131
Postnatally, the standard
129
Asso-
130
Meconium peritonitis is a result of in utero small bowel
perforation and subsequent extrusion of meconium
intraperitoneally. Calcifications can be seen in the peritoneum, outlining bowel or liver (Fig. 38-15). When the
extruded meconium becomes walled off in the peritoneum and develops a heterogeneous cystic appearance,
ABDOMINAL WALL
Embryology
The embryonic abdominal wall develops from the lateral
plate mesoderm and endoderm in later embryonic
Chapter 38 ■ The Fetal Abdominal Wall and Gastrointestinal Tract 1339
A
B
C
FIGURE 38-15. Meconium peritonitis. A, Sagittal view of fetus with a single calcification (arrow) in the abdomen with shadow-
ing. B, Transverse view of the abdomen with multiple punctate calcifications (arrows) scattered within the fetal abdomen, without shadowing. Note the small amount of ascites (arrowhead). C, Oblique sagittal view of the torso shows multiple calcifications on the peritoneal
surface of the liver in a fetus with a meconium pseudocyst (arrowhead), with an irregularly calcified wall. (From McNamara A, Levine D.
Intraabdominal fetal echogenic masses: a practical guide to diagnosis and management. Radiographics 2005;25:633-645.)
1340 PART IV ■ Obstetric Sonography
development (days 16-26). Each lateral plate splits horizontally into the parietal and visceral mesoderm.
space between these layers becomes the body cavity
(coelom or celum).
5
The coelom differentiates into the
132
The
peritoneal, pericardial, and pleural cavities. Normal
FIGURE 38-16. Meconium pseudocyst. Note cyst with
debris with calcified rim (arrows).
development of the abdominal wall requires enfolding
of the lateral plate around the coelom in several dimensions: caudally, cephalad, and laterally. In the normal
enfolding process, the lateral folds come together before
the normal gut rotation, leaving a physiologic gut herniation into the coelomic outpouching of the umbilical cord
insertion
133
(Fig. 38-18). This herniation is usually
visible on ultrasound from 9 to 11 weeks. In several large
series of sequentially scanned fetuses, the bowel was no
longer evident at the base of the umbilical cord in normal
fetuses after 11 weeks.
7
Therefore, if prominent material
is seen at the cord insertion site, and it is unclear whether
it is caused by an abdominal wall defect or physiologic
bowel herniation, a follow-up scan in 1 week will resolve
the issue.
Abdominal wall defects include gastroschisis, omphalocele, ectopia cordis, cloacal exstrophy, and amniotic
band syndrome (limb–body wall defects). The overall
incidence of abdominal wall defects is 6.3 per 10,000
pregnancies.
134
Because of the loss of integrity in the
epidermal covering, abdominal wall defects are associated with elevations of maternal serum alpha-fetoprotein
(MS-AFP). In the last 3 decades, with both maternal
serum screening and fetal anatomic surveys recommended and available in the second trimester, the majority of abdominal wall defects are diagnosed in the second
trimester. Centers that practice universal first-trimester
screening have documented confirmation of diagnoses
before 14 weeks.
6,7
With increased access to early scanning in the United States, earlier diagnosis is expected
to become more common.
A B
FIGURE 38-17. Enteric duplication cyst. A, Note the characteristic double line around the wall, which distinguishes a gut
duplication from other abdominal cysts. B, Atypical appearance of gastric duplication cyst with echogenic material (arrow). Note how
cyst impinges on stomach. (B from McNamara A, Levine D. Intraabdominal fetal echogenic masses: a practical guide to diagnosis and manage-
ment. Radiographics 2005;25:633-645.)
Chapter 38 ■ The Fetal Abdominal Wall and Gastrointestinal Tract 1341
A
B
C D
FIGURE 38-18. Physiologic gut herniation. A, Physiologic gut herniation into the coelomic outpouching of the umbilical cord
insertion at 9 weeks. B, Ninety-degree rotation of the bowel at the axis of the superior mesenteric artery. C, At 12 weeks the bowel reverts
to its intra-abdominal placement, undergoing an additional 180-degree rotation along the axis of the superior mesenteric artery. D, In a
fetus at 11 weeks, prominent material is seen at the cord insertion site (arrow). At 12 weeks this fetus was confirmed to have a normal
abdominal cord insertion.
Gastroschisis
Gastroschisis is a full-thickness paraumbilical defect of
the abdominal wall, most often right sided, although
when diagnosed in later pregnancy, the paraumbilical
location may be more difficult to demonstrate on prenatal ultrasound. Unlike omphalocele, free-floating loops
of bowel in the amniotic fluid are the key finding
on ultrasound. In population-based studies in Europe,
Australia, and Japan, the incidence of gastroschisis has
increased from 0.4 to 1.6 per 10,000 up to 1.4 to 4 per
10,000 live births during the last 25 years.
135-139
There
is no gender predilection in the affected fetuses. There
is a dramatically increased incidence in teenage mothers,
with the largest population-based study showing a
tenfold increased incidence in 15- to 19-year-old compared to 20- to 25-year-old women; the incidence in the
15- to 19-year-old age group also increased from 4.0 to
26.5 per 10,000 births.
136
Particularly in young women, gastroschisis is associ-
ated with use of tobacco, illicit drugs, and pseudo-
ephedrine.
associated with aneuploidy (0%-1.3%).
risk of non-GI anomalies is also small, up to 3%.
135,136,139-141
Gastroschisis is infrequently
139,142-144
142,143,145
The
Increased risk of preterm birth weight (<10%) and a
relatively high stillbirth rate (4.5%-12%) have been
reported.
stenosis, perforations, or volvulus) are common (11%31%).
result from the requisite malrotation or nonrotation in
the herniated bowel, often through a relatively small
abdominal wall defect. Morbidity and mortality are
more common in infants diagnosed postnatally with
these complications.
the abdominal wall defects in fetuses with gastroschisis.
One theory cites isolated vascular compromise of the
abdominal wall in the first trimester, which is supported
by the increased relative risk in teenage mothers who use
vasoactive substances. Other proposed etiologies include
failed development of the mesoderm and the lateral
mesodermal enfolding.
for the paramedian full-thickness defect.
ward when the defect is limited, and free-floating loops
of bowel are identified intra-amniotically. Most often the
defect is paraumbilical, right sided (Fig. 38-19; Video
38-3), and limited. Less often the defect extends upward
or laterally. Extended abdominal wall defects with freefloating bowel or liver are less common. Gastroschisis
with inability to identify abdominal wall on prenatal
138,142,146
134,143,145
Associated GI abnormalities (atresias,
These anomalies are hypothesized to
134,145,146
It is unknown whether one or more etiologies explain
147
However, these do not account
The diagnosis is gastroschisis is relatively straightfor-
1342 PART IV ■ Obstetric Sonography
B
ACI
A
C D
E
B
SB
External loops
of bowel
FIGURE 38-19. Gastroschisis. A, Schematic of the full-
thickness abdominal wall defect lateral to the umbilical cord.
B, Transverse fetal abdomen with the abdominal cord insertion to the
side of the extruded loops of bowel (B) in the amniotic fluid. C, Sagittal view of a fetus with gastroschisis with bowel (arrow) visible between
the legs. D, Gastroschisis with dilated intra-abdominal loops of small
bowel (SB). This fetus was born with torsion of loops of bowel at the
cord insertion site, but they were able to be reduced without requiring
bowel resection. E, Gastroschisis with dilated loops of bowel floating
in the amniotic fluid.
ultrasound has a significantly poorer prognosis than the
more common limited defects, with no survivors in one
large series. First-trimester diagnosis is possible.
136,148
Initial management of gastroschisis involves detailed
sonographic fetal evaluation and genetic counseling.
Although risk of aneuploidy is low, amniocentesis is not
unreasonable; given the young age of most mothers, the
low risk of aneuploidy is still above age-based risk expectation for this population. Care must be taken to assess
if the borders of the defect can be delineated, looking for
the defect extending into the pelvis or up to the sternum.
Gastroschisis is associated with IUGR, fetal demise,
149
and evolving GI obstructions or perforations, serial sonography is recommended to continue to evaluate fetal
growth and evaluate the bowel. Dilated stomach and
dilated loops of bowel, either within the fetal abdomen
or within the amniotic cavity, can be identified.
The increased stillbirth rate has led to many series
attempting to predict fetuses at risk for in utero demise
or poor postnatal outcome and to help optimize timing
Chapter 38 ■ The Fetal Abdominal Wall and Gastrointestinal Tract 1343
A
B
C D
FIGURE 38-20. Omphalocele. A, Schematic of membrane covered omphalocele containing only bowel. B, Transverse abdomen
with loop of bowel herniated into base of umbilical cord (arrow) at 13 weeks. C, Isolated loop of bowel in omphalocele sac. This is a
small, small bowel–only omphalocele. The fetus had a karyotype of trisomy 18. D, Schematic of bowel and liver herniated into omphalocele sac.
Continued
of delivery. Some series have reported that a dilated
fetal stomach is associated with both increased risk of
fetal demise and postnatal morbidity.
152
et al.,
however, showed that the presence or absence
146,150,151
Badillo
of bowel findings failed to predict in utero or postnatal
outcome. Loss of reactivity on fetal heart rate monitoring
is a more reliable predictor of poor fetal outcome.
153
Due
to concern that prolonged in utero exposure of the bowel
to amniotic fluid may worsen outcomes, two trials
looked at outcome in fetuses born preterm (average, 35
weeks) versus those delivered at term or for abnormal
fetal testing.
154,155
Neither trial showed an improved
outcome in preterm fetuses. Based on this information,
although sonographic monitoring of the fetus is recommended throughout pregnancy, in addition to antenatal
testing, preterm delivery is recommended only in cases
of abnormal fetal testing, with or without growth delay.
Omphalocele
Omphalocele is a midline abdominal wall defect into
which the abdominal contents are extruded. It is covered
by amnion and peritoneum (Fig. 38-20). The incidence
of omphalocele varies geographically, from 0.6 per
10,000 births in Japan
British Isles.
143
British rates are also increased compared
to European centers in the EUROCAT trials across
the same time periods.
omphalocele is most common in women 35 to 40 years
139
Omphaloceles have a higher risk (10%-30%) of
old.
chromosome abnormalities than gastroschisis.
most common aneuploidies are trisomies 13 and 18,
with trisomy 21, 45,X, and triploidy being reported.
139
to 6 per 10,000 births in the
142,156
In contrast to gastroschisis,
139,143
The
157,158
Fetuses with liver herniated into the omphalocele
sac have a lower risk of chromosomal abnormality
1344 PART IV ■ Obstetric Sonography
AC
E
F
G
FIGURE 38-20, cont’d.
G, Omphalocele. It is difficult to tell if the material in the sac is liver and/or bowel.
than those with small bowel–only omphalocele (Fig.
38-20, C ).
Omphalocele has a 55% to 58% risk of associated
anomalies,
143,159
including midline defects (cardiac,
clefting, and spinal/vertebral anomalies), clubfoot, and
central nervous system anomalies.
common association with aneuploidies and multisystem
anomalies, most published rates of pregnancy termination are high, potentially biasing outcome data. Inherited syndromes associated with omphalocele include
autosomal dominant, autosomal recessive, and X-linked
recessive.
160
Omphalocele is also part of several syndromes, most notably Beckwith-Weidemann (Fig.
38-21). Beckwith-Weidemann syndrome is associated
with mutation or deletion of imprinted genes within the
chromosome 11p15.5 region. Its hallmarks are omphalocele, macroglossia, and gigantism in the newborn.
The etiology of development of omphalocele is multifactorial when isolated.
failure of closure of the lateral mesodermal folds.
Identification of omphalocele in the second trimester
is straightforward when close attention is paid to the
abdominal cord insertion to ascertain that there is no
evidence of bowel herniation into the base of the umbilical cord. In the first trimester, physiologic umbilical
E and F, Transverse and sagittal abdominal image of omphalocele with herniated liver and bowel.
herniation can be mistaken for early omphalocele
detection. This finding does not persist into the second
trimester, so even small herniations into the umbilical
cord (Fig. 38-20, A-C ) are diagnostic of omphalocele in
159
Because of the
the second trimester. Liver can also be herniated into
larger lesions (Fig. 38-20, D-F ). Liver is never physiologically herniated, and if seen in the late first trimester,
this should be considered abnormal. During the evaluation, attempts should be made to assess the boundaries
of the abdominal wall lesion for appropriate parental
counseling. The finding of fetal omphalocele should
trigger a detailed fetal evaluation, including fetal echocardiography, because of the frequency of cardiac
156
defects.
consideration of fetal chromosomal evaluation. Serial
fetal sonography should be performed, as well as fetal
testing. Parents should be counseled about the risk of
161
Other hypotheses include the
162
stillbirth.
Ectopia Cordis
Ectopia cordis is a midline fetal defect with all or part of
the heart extruded out of a sternal defect, with or without
a membrane (Fig. 38-22). Whether part of an extended
gastroschisis or omphalocele or an isolated finding, the
Genetic counseling is recommended, with
139
Chapter 38 ■ The Fetal Abdominal Wall and Gastrointestinal Tract 1345
A B
FIGURE 38-21. Beckwith-Weidemann syndrome. A, Transverse view of abdomen demonstrates an omphalocele (calipers).
B, View shows an 8-cm-thick placenta, consistent with placentomegaly.
167
et al.
proposed that these defects result from a developmental field disorder, which is now the accepted
working hypothesis. Ectopia cordis therefore may be
present independent of or associated with thoracoabdominal syndrome.
V
FIGURE 38-22. Ectopia cordis. Transverse color Doppler
view of the fetal chest shows that the heart is outside the divergent
sternum; V, ventricle. (Courtesy Leo Drolshagen, MD, Fort Smith,
Ariz.)
prognosis is poor, although survivors have been
reported.
sis.
163
164,165
Trisomy 18 is associated with this diagno-
Pentalogy of Cantrell was first described as a
combination of abnormalities, including diaphragmatic
and ventral hernias, hypoplastic lung, and cardiac anomalies such as transposition of the great vessels and patent
ductus arteriosus.
166
Later, geneticists recommended
including fetuses or infants with ectopia cordis and other
midline defects within this categorization. With this
definition, prenatal diagnosis can only be suspected, and
not confirmed in utero. The NCBI Online Mendelian
Inheritance in Man (OMIM) registry recommends the
term thoracoabdominal syndrome for the combinations of these disorders, now including other midline
defects such as facial clefting and encephalocele. Martin
Amniotic Band Syndrome and
Limb–Body Wall Complex
Amniotic band syndrome can affect any part of the fetus.
If a band has disrupted development of the anterior
abdominal wall, the defect can appear similar to a gastroschisis (Fig. 38-23). Extended and complex midline
defects of the abdominal wall or thorax are generally
categorized as limb–body wall complex or body stalk
anomaly.
168
These defects are often one aspect of a fetus
with multiple anomalies and are associated with limb
or spinal defects, craniofacial defects, exencephaly, or
encephaloceles. The incidence is 1.3 per 10,000 pregnancies at 11 to 14 weeks,
169
with spontaneous pregnancy loss leading to decreased incidence later in
gestation and at birth. Many suggest that limb–body wall
complex encompasses two subtypes of midline defects
with entirely different etiologies.
170-175
The first type,
phenotypically characterized by craniofacial defects,
amnion bands, and adhesions, is caused by vascular
disruption or amnion rupture in very early pregnancy.
The second type has no craniofacial defects but rather
urogenital anomalies (including cloacal and bladder
exstrophies), anal atresia, and abnormalities of the placental attachment site, as well as persistence of the extraembryonic coelom. This type is thought to be caused by
fetal maldevelopment.
Sonographic diagnosis is suggested when there is
extrusion of abdominal contents into amniotic fluid with
the presence of a shortened and two-vessel umbilical
1346 PART IV ■ Obstetric Sonography
A
FIGURE 38-23. Amniotic band syndrome. A, Transverse view of abdomen shows anterior abdominal wall defect. B, View of
lower extremity shows constriction ring caused by amniotic bands. The constellation of findings is consistent with amniotic band
syndrome.
173
cord.
Oligohydramnios is common. Distinguishing
the subtypes may not be possible because of the difficulty
visualizing the fetal face. Fetal MRI may be helpful in
illustrating these complex abdominal wall defects.
172,176
Although the subtypes have different developmental etiologies, the prognosis for both types, in the absence of
amniotic fluid, is universally fatal.
B
phy (Fig. 38-25). This group of birth defects consists
of omphalocele, exstrophy of the cloaca, imperforate
anus, and spinal abnormalities. Genital abnormalities
are also common.
182
This disorder is sporadic, occurring
at a higher rate in monozygous than dizygous twins,
suggesting a vascular component.
The OEIS defects probably result from failure of
183
fusion of the abdominal cloaca and exstrophy of the
Bladder Exstrophy
Bladder exstrophy–epispadias complex (BEEC) is
defined in OMIM as the combination of infraumbilical
abdominal defects, including the pelvis, urinary tract,
and external genitalia.
177
Both familial and sporadic cases
occur. The etiology is multifactorial; many fetuses have
multisystem anomalies, including kyphoscoliosis, renal
defects, and clubfoot.
178,179
There is no reported associa-
tion with aneuploidy.
Sonographic diagnostic criteria include the presence
of an infra-abdominal mass and inability to visualize a
bladder. There is an inferiorly displaced umbilical cord,
usually with a unilateral umbilical artery (Fig. 38-24).
Neonatal outcome has low mortality, but repair of these
defects is complex, often requiring staged procedures
with a mixed outcome, to maintain continence and
functional genital tissue.
180,181
common cloaca that receives ureters, ileum, and a rudimentary hindgut. Additional findings occur in the
genital tubercles and pubic rami, with incomplete development of the lower vertebrae. Imperforate anus, cryptorchidism, and epispadias occur in males, with anomalies
of the müllerian duct derivatives in females, as well as a
wide range of urinary tract anomalies, including renal
agenesis.
161
Criteria for sonographic diagnosis of OEIS are nonvisualization of the bladder associated with a visualized
persistent cloaca, presence of an omphalocele, and spinal
defects, typically neural tube defects or tethered cord.
Single umbilical artery is a common associated finding.
Although fetuses also have genital abnormalities, defining these in utero is difficult.
Diagnosis of OEIS has been reported as early as
95
13weeks.
Tiblad et al.
184
185
reported 100% diagnostic
accuracy in the second trimester, although other
series reported diagnostic difficulties differentiating
Omphalocele-Exstrophy–
Imperforate Anus–Spinal Defects
Omphalocele-exstrophy–imperforate anus–spinal defects
(OEIS) complex was formerly known as cloacal exstro-
from limb–body wall complex and pentalogy of
Cantrell.
182,183,186
Once this diagnosis has been made,
genetic counseling is suggested. In patients continuing
pregnancy, amniocentesis may be considered to identify
gender prior to birth.
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