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Renal Agenesis

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    Renal tract     dilation and     hyronephephrosis
      Upper renal       tract       obstruction
      Lower renal       tract       obstruction
    Multicystic     dysplastic     kidney
    Polycystic kidney
    Renal agenesis


Introduction Antenatal Postnatal West Midlands Data



Renal agenesis anomaly may affect one or both kidneys and has an unknown aetiology. Bilateral renal agenesis (BRA) occurs sporadically but there is some evidence that genetic factors are involved and it is important to screen both parents and siblings. BRA can also occur as part of syndromes such as VATER and branchio-oto-renal syndrome but it is more commonly an isolated finding. BRA occurs more frequently in males (2:1) and is incompatible with life.

Unilateral renal agenesis (URA) is much more common than BRA and is associated with some ear and ureteral anomalies.

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Renal agenesis may not be immediately apparent on ultrasound, but the bladder is never seen and from 16 weeks gestation it becomes apparent that there is reduced, or no liquor around the fetus. Doppler studies can be used to distinguish BRA from severe intrauterine growth retardation.

Severe oligohydramnios has devastating consequences for the development of the fetal lungs. If there is no liquor production the normal development of the fetal lungs cannot occur. Amniotic fluid levels are maintained by a balance between excretion of fetal urine into the amnion and the swallowing of fluid and its transfer to the mother via the placenta.

Thoracic compression and pulmonary hypoplasia result from reduced amniotic fluid. This compression of the embryo by the uterine wall and lack of liquor may result in a sequence of abnormalities called Potter syndrome these include severe talipes and limb contractures from reduced movement. Potter's facies include a square "parrot-beaked" nose, hypomandibulosis, epicanthic folds, a rounded head, wide set eyes, and low set ears. Visualisation of other defects may be hampered by the squashed position of fetus.

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BRA is incompatible with life. URA may be asymptomatic but sometimes the other kidney may be hypertrophied and more susceptible to damage due its size.

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Information to follow

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© Perinatal Institute 2011