Objective To determine the performance of screening for pre-eclampsia (PET) by maternal characteristics and uterine artery pulsatility index (PI) at 11 + 0 to 13 + 6 weeks' gestation. Methods

Objective To determine the performance of screening for preeclampsia by maternal characteristics, urine albumin concentration and albumin-to-creatinine ratio (ACR) at 11 +0 to 13 +6 weeks.Design Prospective cross-sectional observational study.Setting Routine antenatal visit.Population A total of 2679 pregnant women at 11 +0 to 13 +6 weeks of gestation.Methods Maternal variables, urine albumin concentrations and ACR of 51 women who developed pre-eclampsia were compared with 2364 women who were unaffected by hypertensive disorders. Regression analysis was used first to determine which of the factors among the maternal characteristics were significant predictors of urine albumin concentration and ACR in the unaffected group and second to determine the contribution of urine albumin concentration and ACR in the prediction of pre-eclampsia.Main outcome measures Development of pre-eclampsia. ResultsIn the unaffected group, log urine albumin concentration and log ACR were influenced by ethnic origin, age, body mass index (BMI), parity and smoking. In the prediction of preeclampsia, significant contributions were provided by log urine albumin concentration, log ACR, ethnic origin, BMI, age, family and history of pre-eclampsia. The median urine albumin concentration and the median ACR in the pre-eclampsia group were significantly higher than those in the unaffected group. However, in screening for pre-eclampsia, the area under the receiver operating characteristic curve was not significantly improved by the combined models than with maternal variables alone. The value of urine albumin concentration was not improved by correcting for the creatinine concentration. ConclusionIn the prediction of pre-eclampsia, urine albumin concentration at 11 +0 to 13 +6 weeks does not provide additional value to maternal variables.