Objective Four: Describe Congenital Disorders of Kidney

Renal agenesis

Congenital failure of one or both kidneys to develop.

Unilateral renal agenesis

Absence or severe underdevelopment of one kidney; the remaining kidney may compensate.

Bilateral renal agenesis

Absence of both kidneys; severe because the fetus has no functioning kidneys to produce urine.

Renal hypoplasia

Congenital condition in which a kidney is present but smaller than normal because it did not fully develop.

Ectopic kidney

Kidney that does not reach its normal anatomical location during fetal development.

Pelvic kidney

Ectopic kidney that remains in the pelvic region rather than ascending to the upper abdomen.

Crossed ectopic kidney

Kidney located on the opposite side of the body from its normal position.

Horseshoe kidney

Congenital fusion of the lower poles of the kidneys, creating a U-shaped structure.

Horseshoe kidney complications

Abnormal positioning or drainage can increase risk of urinary obstruction, infection, and stones.

How do unilateral and bilateral renal agenesis differ?

Unilateral: one kidney absent or severely underdeveloped; bilateral: both kidneys absent and the condition is much more severe.

How does renal hypoplasia differ from renal agenesis?

Hypoplasia means the kidney is present but abnormally small; agenesis means it failed to develop.

What is an ectopic kidney? Give two examples.

A kidney in an abnormal location; examples include a pelvic kidney and a crossed ectopic kidney.

What is a horseshoe kidney and what complications can occur?

The lower kidney poles fuse into a U shape; abnormal positioning/drainage can increase obstruction, infection, and stone risk.