Prediction of pre-eclampsia: comparative analysis of two screening tests

Pre-eclampsia is a major cause of maternal and perinatal morbidity and mortality. Unfortunately, in spite of extensive research worldwide, still we lack an effective screening test for pre-eclampsia. The aim of the current study is to assess the importance of micro-albuminuria and uterine artery Doppler resistance index as a screening test for pre-eclampsia during antenatal period. The study is a prospective audit. The study population consisted of 160 antenatal mothers attending the outpatient department. Test for micro-albuminuria was done at 14 weeks, 18 weeks, 28 weeks and 34 weeks of gestation. Uterine artery Doppler resistance index (0.58 taken as cut-off) was recorded at 18 weeks of gestation. The subjects were followed up till delivery for development of pre-eclampsia. Sensitivity, specificity, positive and negative predictive value (along with confidence interval and diagnostic odd's ratio) of the tests were calculated. Sensitivity, specificity, positive and negative predictive value of micro-albuminuria was recorded as 66.67%, 93.24%, 44.44% and 97.18% respectively. Those of uterine artery Doppler resistance index were 33.33%, 95.96%, 40% and 94.67% respectively. Diagnostic odd's ratio of micro-albuminuria and uterine artery Doppler resistance index were 27.600 and 11.833 respectively. Confidence interval and diagnostic odd's ratios show that uterine artery Doppler study is a better screening test amongst the two. Both the tests being non-invasive in nature and having high specificity and high negative predictive value can be utilised in community-based antenatal care for identifying women who need intensive vigilance.