Advancing Prenatal Assessment in Congenital Diaphragmatic Hernia

By Suzanne Debari, BS, RDMS, RVT, RT(R)
Fetal Imaging Operations Manager, Richard D. Wood Jr. Center for Fetal Diagnosis and Treatment

Congenital diaphragmatic hernia (CDH) remains one of the most significant congenital anomalies managed in maternal-fetal medicine, occurring in approximately 1 in every 2,500–3,000 live births. CDH results from incomplete formation of the diaphragm during fetal development, allowing abdominal organs — most commonly the stomach, bowel and liver — to migrate into the thoracic cavity. This herniation compresses the heart and lungs, leading to pulmonary hypoplasia, pulmonary hypertension and frequently reduced cardiac output, particularly of the left ventricle. CDH may occur on the left, right or rarely both sides, and early, accurate prenatal diagnosis is essential because affected newborns require immediate, specialized care at delivery.

The Richard D. Wood Jr. Center for Fetal Diagnosis and Treatment (CFDT) at CHOP has developed one of the most experienced and comprehensive CDH programs in North America. We care for more babies with CDH than any other hospital globally, across the full spectrum of severity, and our surgical team is highly skilled in every repair approach currently available. This experience is supported by our world-leading fetal imaging program, which utilizes the most advanced modalities to deliver precise prenatal assessments that guide perinatal management and postnatal planning.

While fetal MRI is integral to our evaluation of CDH, high-resolution gray-scale ultrasound and color Doppler imaging remain foundational tools — particularly in determining liver position. In left-sided CDH, assessing whether the liver has herniated into the thorax is critically important because intrathoracic liver position is strongly associated with more severe pulmonary hypoplasia and higher overall morbidity. However, determining liver position on ultrasound can be technically challenging, especially when the anatomy is distorted by herniation.

To address this challenge, our team has recently identified a promising new ultrasound marker for evaluating liver position in fetuses with left-sided CDH. This marker relies on color Doppler visualization of the umbilical vein and ductus venosus in a coronal view. In cases where the liver is herniated into the chest (“liver up”), the umbilical vein and ductus venosus demonstrate a characteristic upward course toward the liver before entering the inferior vena cava. This configuration creates a distinctive “candy cane” appearance. 

Preliminary findings from our research show that this candy cane sign offers excellent interobserver agreement along with high sensitivity and positive predictive value for detecting intrathoracic liver position. As we continue to validate this marker in larger cohorts, it has the potential to become a valuable addition to routine prenatal imaging assessment for left-sided CDH — enhancing diagnostic confidence and supporting more nuanced counseling for families. 

At the CFDT, advancing diagnostic precision is central to our mission. Innovations such as the candy cane sign reflect our ongoing commitment to improving prenatal evaluation and optimizing outcomes for babies and families facing CDH.

Our team recently found that in fetuses with left-sided CDH where the liver is herniated into the chest, the umbilical vein and ductus venosus demonstrate a characteristic upward course toward the liver before entering the inferior vena cava. This creates a distinctive “candy cane” appearance that offers a promising new ultrasound marker for evaluating liver position.