ABSTRACT
Alpha-fetoprotein (AFP) levels were measured in 25 pregnancies with renal dysfunction
of the fetus. Oligohydramnios was found in 14 of 16 patients diagnosed by 20 weeks
of gestation and in all of those diagnosed later. AFP levels in maternal serum were
normal in 17 (68%), elevated in five (20%), and low in three patients (12%). AFP serum
levels up to 24 weeks of gestation were significantly higher than after 24 weeks.
AFP levels in amniotic fluid obtained from amniocentesis in six patients were normal
or slightly elevated. We suggest that the concentration of AFP in amniotic fluid and
maternal serum does not only depend on the physiologic proteinuria of the immature
fetal kidneys but also on the permeability of the not yet keratinized fetal skin and
the diluting volume of the amniotic fluid.
