NONDYSPLASTIC FETAL RENAL HYPOPLASIA ASSOCIATED WITH SEVERE OLIGOHYDRAMNIOS - CLINICAL, PATHOLOGICAL, AND MORPHOMETRIC FINDINGS

Two fetuses with severe bilateral renal hypoplasia are described; both diagnoses were made following elective abortion for oligohydramnios a nd suspected renal dysplasia. A 20-week female fetus (46,XX) had pulmo nary hypoplasia and very small kidneys (7% of expected weight) that we re normally shaped and nondysplastic, with well-formed medullae and me tanephric blastema and markedly diminished cortices with only rare glo meruli. A 23-week male fetus (46,XY) had small kidneys (13% of expecte d weight) that were nondysplastic, normally shaped, and histologically well organized with moderately decreased numbers of glomeruli. Isolat ed bilateral renal hypoplasia has not previously been well characteriz ed in fetuses; the presence of oligohydramnios (both cases) and pulmon ary hypoplasia (one case) suggests that this finding is associated wit h impaired fetal renal function and may adversely influence neonatal s urvival.