Limb-body wall complex

Prenatal ultrasound can detect limb-body wall complex (LBWC) as early as the first trimester (usually by the end of the first trimester).^[1][2] The majority of cases discussed in the medical literature have been diagnosed in the second or third trimester.^[3] In a 2014 report of a diagnosis made in the first trimester, the authors stated that a combination of two- and three-dimensional ultrasounds was useful for establishing the diagnosis and differentiating from other abdominal wall defects.^[3]

The hallmarks of LBWC on prenatal ultrasound include:

• thoracoschisis (fissure of the thoracic wall) and/or abdominoschisis (fissure of the abdominal wall)
• neural tube defects
• severe scoliosis (curvature of the spine)
• positional deformities (abnormalities caused by a fetal environment that restricts fetal movement or causes significant fetal compression)
• abnormality of fetal membranes

Generally, the diagnosis is based on the presence of any 2 of the following 3 features:

• exencephaly (when the brain is outside of the skull) and/or encephalocele (sac-like protrusion of the brain and its membranes through an opening in the skull) with facial clefts (openings or gaps in the face)
• thoracoschisis and/or abdominoschisis
• limb defects

Unfortunately, LBWC is considered incompatible with life (it is fatal). The majority of affected pregnancies end in fetal demise. Due to the poor prognosis, early prenatal diagnosis is important so pregnancy management options, including termination of pregnancy, can be discussed.^[1] Early termination of pregnancy and avoidance of surgical intervention are often recommended.^[1][2] It is important to differentiate LBWC from other anterior abdominal wall defects, such as gastrochisis and omphalocele, because these have a more favorable prognosis compared to LBWC.^[1]