OBGY Radiology

Case 11
G3/A2 mother, consanguineous marriage. Images of 17-weeker fetus. Head is in the pelvis. Scan pictures provided are that of the heart, and at the level of the abdomen. What is the most likely diagnosis?
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Imaging Findings

AV canal defect on 4-chamber view of heart. Fetal karyotyping was performed by cordocentesis for Trisomy 21, and was negative. Though stomach bubble was not seen on the first scan (Fig 2), it was detected on a subsequent re-scan. Patient after counseling decided to terminate the pregnancy. Autopsy confirmed all the findings. Additional truncus arteriosus was found on autopsy. Situs inversus totalis was found on autopsy (suspected on antenatal scan, in view of the fact that in a cephalic presentation, apex was pointing away from transducer).

Final Diagnosis
Atrioventricular septal defect.

A common atrioventricular valve is found when there is a defect in both the atrial and ventricular septa at the crux of the heart, at the normal point of insertion of the two atrio-ventricular valves. The appearance is of a single valve opening astride the crest of the ventricular septum.

This is one of the commonest forms of heart disease seen in prenatal life, accounting for about 17% of cardiac anomalies, and is found usually in 2 situations: associated with complex cardiac anomalies or associated with Trisomy 21. When a diagnosis is made, fetal karyotyping should be performed; prognosis depends on presence of associated cardiac or extra-cardiac anomalies.

Ultrasound in Obstetrics and Gynaecology. David Cosgrove, 1994. PG 370

Dr. L Raghunath, Hemavathi Hospital, Hassan, Karnataka
Dr Ramamurthy, Srinivasa Scan Center, Bangalore