Fetal urine production estimated with ultrasound. The lower limit of normality is illustrated in a case with severe hypoplasia of the kidneys.

Urine production and weight deviation in a growth-retarded fetus with oligohydramnios was estimated by ultrasound on four occasions between weeks 27 and 33 of gestational age. The fetus demonstrated facial features typical of Potter's syndrome. Although this syndrome is associated with bilateral renal agenesis, the fetus in the present case presented with hypoplastic kidneys. Urine production was reduced when measured on three occasions but was surprisingly normal at week 31. In this report, we describe a way to assess urine production in a fetus.