How severity is estimated

Educational, not medical advice. Your team knows the specifics of your pregnancy. If you have an urgent concern, call your physician or 911.

Module 1 — Starting the Journey · Episode 2

No single test or number defines a baby’s outcome. A fetal center estimates severity by bringing several measurements together.

Ultrasound

The anatomy ultrasound is usually where CDH is first seen. Detailed follow-up scans track growth and the position of the stomach, bowel, and liver. Some centers also calculate a lung-to-head ratio (LHR) from ultrasound.

Fetal MRI

At Texas Children’s, fetal MRI is central to the evaluation, giving a clearer three-dimensional view than ultrasound alone. Two measurements matter most:

• Observed-to-expected total fetal lung volume (O/E-TFLV) compares your baby’s measured lung volume to what would be expected at that gestational age. It is one of the better available tools for estimating how developed the lungs are.
• Percent liver herniation (%LH) describes how much of the liver has moved up into the chest. More liver in the chest is generally associated with greater severity.

The heart and genetics

A fetal echocardiogram checks for heart differences that can accompany CDH. Because CDH is sometimes part of a broader genetic picture, genetic testing such as amniocentesis may be offered, though many babies have no identifiable genetic cause.

Why measure at all

The goal is not to label your baby, but to prepare, so the right team, equipment, and plan are ready the day your baby is born. These results are interpreted together across specialties, never as a single verdict.

Next in Module 1: What happens after diagnosis? · Back to Module 1