Urinary excretion of N-acetyl-beta-D-glucosaminidase in normal and complicated pregnancy.

The urinary excretion of N-acetyl-beta-D-glucosaminidase activity, a sensitive indicator of renal tubular injury, was monitored during and after pregnancy. During normal pregnancy, enzymuria increased progressively to levels 3-4 times above normal in the third trimester. In diabetic mothers, enzyme excretion followed a similar pattern, but was generally higher than in uncomplicated pregnancies. Also in preeclampsia, enzymuria tended to be higher than in normal pregnancy. Enzyme excretion normalized about a year after normal pregnancies, but remained elevated in diabetic subjects and in patients who had developed preeclampsia. This latter finding indicates that marginal persistent renal damage may occur during preeclampsia.