Renal disease in women with severe preeclampsia or gestational proteinuria.

OBJECTIVE: To identify women with severe preeclampsia or severe gestational proteinuria at high risk of having underlying renal disease.
METHODS: Between 1980 and 1999, 86 Japanese women who had severe hypertension, severe proteinuria, or both during pregnancy had postpartum needle biopsies of their kidneys. Diagnoses before biopsies were severe preeclampsia in 74 women and severe gestational proteinuria in 12. We compared clinical characteristics, such as antepartum hematuria and postpartum proteinuria, and maternal and neonatal outcomes with regard to presence of renal disease.
RESULTS: Nineteen of 86 women (22.1%, 95% confidence interval [CI] 13.9%, 32. 3%) were diagnosed with underlying renal disease. Immunoglobulin A nephropathy was present in 12. Women with renal disease had a significantly earlier onset of proteinuria than those without (median 11 versus 32 weeks' gestation, P <.001). Eighteen of 19 women with renal disease had proteinuria, hypertension, or both before 30 weeks' gestation. Ten of 12 women with severe gestational proteinuria (83.3%, 95% CI 51.6%, 97.9%) had underlying renal disease. Eight of the 19 women had antepartum hematuria, and seven had elevated serum immunoglobulin A levels. In women with severe preeclampsia, onset before 30 weeks' gestation was the best predictor of underlying renal disease (odds ratio 34.1, 95% CI 3.8, 304.5). Women with renal disease had lower rates of severe hypertension (nine of 19 versus 59 of 67, P <.01) and small-for-gestational-age infants (four of 19 versus 34 of 67, P <.05) than those without renal disease.
CONCLUSION: Women who had gestational proteinuria or preeclampsia before 30 weeks' gestation were more likely to have had underlying renal disease.