Prenatal ultrasound diagnosis and management of body stalk anomaly: analysis of nine singleton and two multiple pregnancies.

OBJECTIVE

To determine prenatal ultrasonographic features and management of fetuses with body stalk syndrome in singleton and multiple gestations.

METHODS

In a retrospective chart analysis we reviewed all cases with body stalk anomaly diagnosed in our prenatal unit between 1994 and 2001. During this time period we adopted a uniform approach to the investigation of cases of body stalk anomaly, including amniocentesis or chorionic villus sampling (CVS) for fetal karyotyping. A general schematic sonographic examination was performed to search for fetal abnormalities and was followed by detailed two-dimensional and color-coded Doppler echocardiography. Nuchal translucency (NT) measurements were performed before 14 weeks of gestation. Postmortem examinations of fetuses were performed following termination by induction with prostaglandin.

RESULTS

Eleven fetuses with body stalk anomaly were diagnosed, including two multiple pregnancies complicated by discordant body stalk anomaly. The typical ultrasonographic features were a major abdominal wall defect, severe kyphoscoliosis, limb abnormalities, neural tube defects, and a malformed, short umbilical cord with a single artery. None of the fetuses demonstrated craniofacial defects. All placentae that were examined showed evidence of persistence of the extra-embryonic celomic cavity. NT measurements were abnormal in all cases. Fetal karyotyping was normal in ten cases. In one case CVS showed a mosaic trisomy 2 (46,XX/47,XX,+ 2). Selective fetocide was performed in one trichorionic-triamniotic triplet pregnancy in early gestation, which was followed by normal development of the remaining healthy dichorionic-diamniotic twins. In a monochorionic-diamniotic twin pregnancy with one affected fetus ultrasound surveillance showed the normal development of the unaffected twin.

CONCLUSIONS

We present a large series of body stalk anomaly, including multiple gestations, with thoraco- and/or abdominoplacental attachment and without craniofacial defects. This specific phenotype may be explained by embryonic maldevelopment. The typical features of body stalk anomaly can be detected by ultrasound by the end of the first trimester, which is important for patient management. Consequently, this anomaly should be distinguished from other fetal abdominal wall defects.