Heart Size in Pregnancy

1. Measurements of cardiac and thoracic diameters were made on 250 routine chest radiographs taken during pregnancy, and on 50 routine chest radiographs of non-pregnant females.

2. The cardiac and thoracic diameters were found to increase during pregnancy, but in the majority of cases the cardiac diameter is not greater than half the thoracic diameter.

3. In those cases where the cardiac diameter is greater than half the thoracic diameter, the accurately determined cardio-thoracic ratio should be assessed using the graph before a diagnosis of cardiac enlargement is made.

4. If any doubt remains as to whether or not the cardiac diameter is enlarged, reference may be made to Jacobs' tables.