|Classification and external resources|
Renal agenesis is a medical condition in which one (unilateral) or both (bilateral) fetal kidneys fail to develop.
Bilateral renal agenesis is the uncommon and serious failure of both a fetus' kidneys to develop during gestation, and is one causative agent of Potter sequence. This absence of kidneys causes oligohydramnios, a deficiency of amniotic fluid in a pregnant woman, which can place extra pressure on the developing baby and cause further malformations. The condition is frequently, but not always the result of a genetic disorder, and is more common in infants born to one or more parents with a malformed or absent kidney. Males are more commonly affected and most infants that are born alive do not live beyond four hours.
Unilateral renal agenesis
This is much more common, but is not usually of any major health consequence, as long as the other kidney is healthy. It is associated with an increased incidence of Müllerian duct abnormalities which are abnormalities of the development of the female reproductive tract and can be a cause of infertility. The odds of a person being born with this condition are roughly 1 in 750. Adults with unilateral renal agenesis have considerably higher chances of hypertension (high blood pressure). People with this condition are advised[by whom?] to approach contact sports with caution.