This leaflet is to help you understand more about the thorax.

Which is the best moment to check my baby's chest?

A routine mid-trimester ultrasound scan is often performed between 18 and 22 weeks of gestation and the main goal is to perform fetal measurements for detection of growth abnormalities and to detect malformations.

What should be evaluated in my baby's chest?

At the routine mid-trimester study, the lungs, heart and diaphragm muscle will be evaluated. In addition, the shape of the thorax and ribs will be noted

How the thorax evaluation is performed in mid-trimester?

At the second or third trimester ultrasound, the examiner will evaluate the thorax shape, the curvature of the ribs, the symmetry of both lungs the absence of masses and the integrity of the diaphragm separating the thorax from the abdomen, noting the normal position of the stomach and liver. The heart is also evaluated.  If unusual structural differences in any chest structures are detected on the routine scan, a more detailed examination of the baby will be warranted to rule out additional abnormalities in other systems. Following second trimester evaluation, your doctor will advise you re the nature of the differences and the prognosis for the baby. In many cases, serial assessment of these structures in the third trimester will be recommended to assess growth of the chest cavity and internal structures and evolution of any unusual findings.


Last updated: April 2024

Thorax Patient Information