A COMPARISON OF THE INACTIVE URINARY KALLIKREIN-CREATININE RATIO AND THE ANGIOTENSIN SENSITIVITY TEST FOR THE PREDICTION OF PREECLAMPSIA

Objective To determine the relation between the inactive urinary kalli krein:creatinine ratio (IUK:Cr) and the angiotensin sensitivity test ( AST) at 28 weeks of gestation and to assess each as a screening test f or pre-eclampsia. Design Prospective interventional study. Subjects Fo ur hundred and fifty-nine normotensive nulliparous women recruited fro m hospital antenatal clinics. Setting John Radcliffe Maternity Hospita l, Oxford, and Queen Charlotte's and Chelsea Hospital, London. Interve ntions A urine sample for IUK:Cr measurement was provided before perfo rming the AST at 28 weeks of gestation. Those women who demonstrated i ncreased sensitivity to angiotensin II were entered into a randomised placebo controlled trial of low dose aspirin for the prevention of pre -eclampsia (CLASP). Main outcome measures The development of pre-eclam psia. Results The IUK:Cr ratio was significantly lower in those women who showed increased sensitivity to angiotensin II (P < 0.0001 Student 's t test). The sensitivity and specificity for detecting pre-eclampsi a were, respectively, 22% and 85% for the AST and 67% and 75% for the IUK:Cr. Low-dose aspirin (60 mg) had no effect on the pregnancy outcom e. Conclusion There appears to be some relation between the IUK:Cr and AST tests in pregnancy. However, in this population, the IUK:Cr ratio was a better screening test for pre-eclampsia than the AST, but overa ll neither test was a powerful predictor for the syndrome.