A Case of Prenatal Left Congenital Diaphragmatic Hernia (19+6 Weeks)
During a routine mid-trimester anatomy scan at 19 weeks and 6 days, an abnormal finding was first suspected in the four-chamber view of the fetal heart.
Initial Impression: Possible Cardiac Abnormality
The four-chamber view demonstrated:
- Rightward displacement of the heart
- Apparent cardiac compression
- Mild mediastinal shift
At this stage, congenital heart disease (CHD) was initially considered.
However, ventricular size appeared relatively symmetric, and no obvious structural intracardiac defect was identified on the available views.
Re-Evaluation of Thoracic Anatomy
Further assessment of the thoracic cavity revealed a crucial finding:
- A round anechoic structure within the left thorax
- Absence of the stomach in its normal abdominal position
- Persistent mediastinal shift
The anechoic structure was consistent with the fetal stomach, now located within the thoracic cavity.
This shifted the diagnostic consideration away from primary cardiac pathology and toward a diaphragmatic defect.
Suspicion of Left Congenital Diaphragmatic Hernia
Although the diaphragmatic defect itself was not sharply visualized on static images, the presence of the stomach in the thorax strongly supports the diagnosis of:
Left congenital diaphragmatic hernia (CDH).
On the current images, definite liver herniation (“liver up”) could not be confirmed. The thoracic contents appeared predominantly cystic, suggesting stomach herniation as the primary component.
Clinical Insight
This case illustrates an important diagnostic principle:
An abnormal four-chamber view does not always indicate a primary cardiac defect.
Cardiac displacement and compression may be secondary to extracardiac pathology, particularly congenital diaphragmatic hernia.
Systematic reassessment of abdominal organ position is essential whenever mediastinal shift is observed.
Recommended Next Steps
Referral to a tertiary center is advised for:
- Detailed fetal echocardiography
- Confirmation of the diaphragmatic defect
- Assessment of lung development
- Multidisciplinary counseling
Transverse view demonstrating the main pulmonary artery (MPA) and ascending aorta(AO).
Measured diameters appear within expected range for gestational age, with no obvious discrepancy in vessel size.
Color Doppler view of the upper mediastinum showing displacement of the great vessels secondary to intrathoracic herniation.
The stomach is visualized within the thoracic cavity, contributing to cardiac compression and rightward mediastinal shift.
Sagittal/ oblique thoracic view demonstrating the fetal heart displaced by an intrathoracic stomach.
The abnormal position of the stomach within the chest results in mediastinal shift and secondary cardiac compression, cosistent with suspected left congenital diaphragmatic hernia(CHD).
4ch view at 19+6wks demonstrating right ward displacement of the heart with mild mediastinal shift.
No obvious intracardiac structural defect is identified on this image.
Despite initial concern for CD based on mediastinal shift, LVOT and RVOT appear identifiable, suggesting that cardiac displacement is likely secondary rather than due to primary structure heart disease.
Transverse view demonstrating the main pulmonary artery (MPA) and ascending aorta(AO).
Measured diameters appear within expected range for gestational age, with no obvious discrepancy in vessel size.
