The antenatal magnetic resonance imaging (MRI) of a third-trimester primipara patient showed a fetus in a vertical position with two separate heads, a common thorax, abdomen, and pelvis with a single pair of upper and lower limbs [Figure 1]. Both heads appeared equal and symmetric with normal brain development [Figure 2]. Two separate upper cervical spinal cords fused to form a single spinal cord in the mid/lower cervical spine level. There was a single heart present in the thoracic cavity. The intra-abdominal organs appeared normal in position, structure, and number [Figure 1]. The findings were confirmed at delivery [Figure 3].
Figure 1.
Coronal T2-weighted turbo spin echo (TSE) showed the fetus in a vertical position with two separate heads, two cervical spinal cords fusing at the mid-cervical spine level, a common thorax, abdomen, and pelvis, and a single pair of upper and lower limbs and a single umbilical cord.
Figure 2.
Coronal T2-weighted turbo spin echo (TSE) the posterior half of the fetal heads showed normally and bilaterally symmetric development of the fetal brains on both sides. Normal appearing cerebral and cerebellar hemispheres, with normal sulci and gyri, were noted.
Figure 3.
Postnatal photograph of the baby delivered at 28 gestational weeks by cesarean section. (Informed consent was taken from the parents of this baby for use of this image).
Questions
What is this variety of conjoint twins called?
Is there any associated cardiac anomaly present in this case?
What is the investigation of choice for evaluation of cardiac anomalies?