Congenital refers to a condition that is present at birth. A congenital condition, defect, or disorder can be inherited or caused by environmental factors. The prognosis of congenital conditions varies widely, ranging from mild to severe. Some congenital conditions may cause life-long disabilities or health issues; others are considered life-limiting in that they are often fatal in the perinatal period. 
You can find the references annotated in each definition above at this link.