ABSTRACT
Renal biopsy was performed in 12 women with the clinical diagnosis of severe, early-onset
preeclampsia at the time of cesarean delivery for the express purpose of aiding future
counseling on the risk of recurrence. The mean gestation at delivery was 30 ± 3 weeks.
The mean birthweight was 1090 ± 505 gm. Four women (33%) were multiparous. Antithrombin
III activity was determined immediately prior to delivery unrelated to clinical care
and as part of other protocols. The biopsy was performed without difficulty in each,
although the sample was inadequate in one patient. The clinical diagnosis of preeclampsia
was confirmed in nine (82%). However, three of the nine had underlying renal disease,
as did the two women without histologic evidence of preeclampsia (42% of the total).
Correlations between laboratory parameters with the histopathologic diagnoses were
sought. Neither uric acid, creatinine, blood urea nitrogen, platelet count, or 24-hour
urinary protein measurements aided the differentiation of the various subgroups. Antithrombin
III activity in women with biopsy-supported preeclampsia (77% ± 12%) was significantly
lower than that in women without histologic evidence of preeclampsia (116% ± 8%).
Antithrombin III activity correctly predicted biopsy findings in at least 9 of 11
(82%). These preliminary findings confirm the high frequency of underlying disease
in women with early-onset preeclampsia. Although low antithrombin III activity does
not differentiate between “pure” preeclampsia and superimposed disease, a normal antithrombin
III activity is reassuring and more consistent with a nonpreeclamptic renal complication
than with preeclampsia.
