Combination of uterine artery Doppler velocimetry and maternal serum placental growth factor estimation in predicting occurrence of pre-eclampsia in early second trimester pregnancy: a prospective cohort study

Abstract

To determine the effectiveness of the combined use of uterine artery Doppler velocimetry (UADV) and estimation of maternal serum placental growth factor (PlGF) levels in early second trimester (20-22 weeks of gestation) in identifying pregnant women at risk of developing pre-eclampsia. Prospective cohort study on 1104 pregnant women with singleton pregnancies between May 2009 and December 2010. UADV and maternal serum PlGF estimation were done at 20-22 weeks' gestation. Association between the two variables and the occurrence of pre-eclampsia was analyzed by logistic regression analysis and odds ratio was computed. The results were considered significant when p was <0.05. Logistic regression analysis showed that both abnormal UADV (odds ratio (OR) 4.1; 95% CI 2.3-7.2; p=0.000) and serum PlGF<188pg/ml (OR 3.6; 95% CI 1.95-6.5; p=0.000) are independent variables in the occurrence of pre-eclampsia, and the difference between the association of these two variables with pre-eclampsia was statistically insignificant as 95% CI values overlap. Multivariate logistic regression analysis showed that a combination of abnormal UADV and serum PlGF<188pg/ml at 20-22 weeks had a very poor association (OR 1.1; 95% CI 0.3-3.8; p=0.938) with the occurrence of pre-eclampsia, as the 95% CI values encompass 1 and p is >0.05. UADV and maternal serum PlGF estimation at 20-22 weeks of gestation are strong predictors of the occurrence of pre-eclampsia when used individually but in combination their association with pre-eclampsia is not significant.