Diagnostic ultrasound ( PDFDrive )

1326 PART IV Obstetric and Fetal Sonography
A
B
C
D
FIG. 38.30 Small Omphalocele. (A) Schematic of membrane covered omphalocele containing only bowel. (B) Transverse image of abdomen
with loop of bowel herniated into base of umbilical cord. The fetus had trisomy 18. (C) Transverse image of abdomen at 26 weeks shows a
bowel-only omphalocele (arrow). The umbilical cord (arrowheads) inserts onto the membrane, which covers the defect. Sp, Spine. (D) Transverse
color Doppler image at 26 weeks shows a bowel-only omphalocele (arrow). The umbilical vessels (arrowheads) course around the bowel, in the
membrane that covers the defect. Sp, Spine. See also Video 38.13.
gastroschisis, fetal weight estimation should be done using
formulas that are based on indices of fetal head and femur length
but not abdominal circumference to avoid underestimation of
fetal weight. 224
here is no evidence that early delivery or cesarean delivery
are associated with improved outcomes. 225 herefore vaginal
delivery following spontaneous onset of labor should be preferred
unless other indications are present for induction of labor or
cesarean delivery. Neonatal outcome is mainly determined by
the presence of associated genetic and/or structural
anomalies. 191,218
Bladder Exstrophy
Bladder exstrophy refers to infraumbilical abdominal wall
defect that results from incomplete closure of the lower
abdominal wall and the anterior wall of the bladder. 226 It is a
rare abdominal wall defect with an incidence of about 1 of 30,000
births. 227
he prenatal diagnosis of bladder exstrophy is mainly based
on the inability to visualize the bladder. he exposed bladder
mucosa may become inlamed and thickened and may therefore
appear as an irregular contour of the lower anterior abdominal
wall (Video 38.14). 228 Another clue for the diagnosis is caudal
displacement of the umbilical cord insertion site (Fig. 38.33).
Associated anomalies include genital abnormalities such as
epispadias, a combination known as bladder exstrophy–
epispadias complex. 226
Neonatal survival is overall good, although the repair of these
defects is complex, oten requiring staged procedures, to maintain
continence and functional genital tissue. 229,230