Figure 11: In body stalk anomaly (right), the lateral, cranial and
caudal folds fail to form, leaving the abdominal content exposed.
Often the heart is close to the defect. The cord is rudimentary and
the membranes attach directly to the fetus.
The maldevelopment of the cephalic, caudal and two lateral folds result in the distinctive anomalies found in body stalk anomaly. A predominantly cephalic defect results in a constellation of anomalies known as pentalogy of Cantrell. It is characterized by an upper midline omphalocele, anterior diaphragmatic hernia, ectopia cordis, sternal cleft and intracardiac defects. In a predominantly caudal defect, one finds a hypogastric omphalocele, exstrophy of the bladder, imperforate anus, partial colonic agenesis and various degrees of intestinal atresias. Other anomalies found include skeletal defects (lordosis and scoliosis), thought to be caused by fetal compression, defects of the chest wall, pericardium, liver, lungs, hypoplastic kidney, and single umbilical artery2,4.
Body stalk anomaly can be distinguished from the short umbilical cord syndrome by the absence of an umbilical cord and the preponderance of 46,XX karyotype. In the short umbilical cord syndrome, the umbilical cord is present and there is a preponderance of 46, XY karyotype.
The anomaly is uniformly fatal. Intrauterine demise is associated with placenta abruption. Since the fetus is attached to the placenta, birth must occur with delivery of the fetus and placenta simultaneously.
The risk of recurrence is not known. Since this anomaly is rare compared to other abdominal wall defects such as omphalocele and gastroschisis, the recurrence risk is probably less than one percent and similar to that of isolated omphalocele.
In one report, the diagnosis was established at 18 weeks3. In this report the diagnosis was made at 12 weeks. Since this anomaly can be diagnosed in early pregnancy and because it is incompatible with life, termination of pregnancy should be considered when the ultrasound findings are identified. Even if the diagnosis is made in late second or early third trimester, interruption of pregnancy should be an option. If the pregnancy is continued, the patient should be counseled that extrauterine survival is impossible, therefore any intervention for fetal distress can be avoided. A history of cocaine use in the first trimester should alert the sonographer to look for anterior abdominal wall malformations as well as other anomalies.
1. Viscarello RR, Ferguson DD, Nores J, et al: Limb-body wall associated with cocaine abuse: Further evidence of cocaine"s tetratogenicity. Obstet Gynecol 80:523-526, 1992.
2. Mann L, Ferguson-Smith MD, Desai M, et al: Perinatal assessment of anterior abdominal wall defects and their prognosis. Prenat Diagn 4:427-435, 1984.
3. Jauniaux E, Vyas S, Finlayson C, et al: Early sonographic diagnosis of body stalk anomaly. Prenat Diagn 10:127-132, 1990.
4. Giacoia GP: Body stalk anomaly: Congenital absence of the umbilical cord. Obstet Gynecol 80:527-530, 1992.
5. Lockwood CJ, Scioscia AL, Hobbins JC: Congenital absence of the umbilical cord resulting from maldevelopment of embryonic body folding. Am J Obstet Gynecol, 155:1049-1051, 1986.
6. Lockwood C: Identifying abdominal wall defects. Contemporary Obstetrics and Gynecology, February 1986.
7. Schmidt W, Yarkoni S, Grelin ES, et al: Sonographic visualization of physiologic anterior abdominal wall hernia in the first trimester. Obstet Gynecol 69: 911-915, 1987.
8. Crelin ES: Development of gastrointestinal tract. Clinical symposia, CIBA.