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Developmental Biology Boot Camp

CDH Severity Classifications

Cartoon depiction of different CDH severity classes. The diaphragm is represented as the center pink region with hernias of varying size.
Cartoon depiction of different CDH severity classes. The diaphragm is represented as the center pink region with hernias of varying size as black shaded areas.

 

Severity

CDH is classified (in order of increasing severity) as type A, B, C, or D. Generally, diseases of type A are quite mild and the patient’s quality of life is minimally affected. Type B and C are intermediate in severity, while type D is often fatal and requires the most extensive intervention. Physicians also often report a lung-to-head ratio (LHR). This is a numeric estimate of the size of the fetal lungs based on what is visible, with LHR>1.0 often foreshadowing favorable clinical outcomes.

Below, note data on persons diagnosed with CDH provided by Vanderbilt Children’s Hospital, compared with the University of Texas CDH Registry. This registry provides data reported by over 50 fetal care centers nationwide. Interestingly, Vanderbilt Children’s Hospital and the CDH Registry report stark differences in the percentage of patients surviving defect D*. This may reflect diagnostic inconsistencies across different centers.

 

Reported numbers by Vanderbilt Children's Hospital compared to the CDH registry.
Reported numbers by Vanderbilt Children’s Hospital compared to the CDH registry.

*These discrepancies warrant more precise classification standards for CDH across different care centers.