Evaluation of the utility of baseline serum hepatic and renal testing in pregnant patients with chronic hypertension.

OBJECTIVE: To determine whether baseline serum hepatic and renal laboratory testing during routine prenatal visits in gravidas with chronic hypertension facilitates the diagnosis of superimposed preeclampsia later in pregnancy. STUDY DESIGN: The study is a historical cohort of pregnant patients with chronic hypertension identified via ICD-9 codes over a 3-year period in a single center. RESULTS: Of the 250 cases reviewed, 73 patients met the inclusion criteria. Of those, 24 developed superimposed preeclampsia and 1 developed eclampsia. In the majority of cases the diagnosis of superimposed preeclampsia was based on severe-range blood pressure and/or new-onset or worsening proteinuria. Only 1 patient had abnormal hepatic transaminase levels at diagnosis. None of the patients were diagnosed with superimposed preeclampsia based solely on abnormal serum hepatic or renal function. Further, the majority of patients had normal baseline testing. Only 3 patients had abnormal baseline serum tests, all of which were elevated transaminase levels. All 3 patients had normalization of their laboratory results on repeat testing prior to delivery, and only 1 of these patients developed superimposed preeclampsia later in pregnancy. CONCLUSION: In our cohort most women with chronic hypertension were diagnosed with superimposed preeclampsia based on exacerbation in blood pressure and/or new-onset or increase in proteinuria. There were no women diagnosed with superimposed preeclampsia on the basis of increased serum hepatic and renal abnormalities alone. In addition, abnormalities in baseline laboratory tests were rare, bringing into question the utility of this testing.