Cite this: Current Controversies in the Diagnosis and Treatment of Patent Ductus Arteriosus in Preterm ... of varying gestational ages. [1] Early shunts are "balanced," or right to left.

Among others, structures such as lungs, placenta, heart, systemic arterial circulation, and the various fetal shunts need to ... circulation (including the ductus venosus) was placed in parallel ...