thanks for your query.
Renal splitting by itself is not a cause of concern.
It is just a deviation from normal development.
However, it requires surgery after birth if associated with obstruction leading to dilatation of pelvi calyceal system, called pelviectasis.
Minimal pelviectasis, that too, on one side, is not worrisome, and often resolves on its own as pregnancy
if it persists at term or increases, please consult Pediatric Surgeon to consider post delivery surgery.
ALso have detailed ultrasound
by High Risk pregnancy specialist to rule out any other associated abnormalities in the baby.
Grade 4 placenta previa
with succenturiate lobe rarely migrates upwards.