Analysis of changes in maternal circulating angiogenic factors throughout pregnancy for the prediction of preeclampsia.

OBJECTIVE: To assess whether changes in maternal angiogenic factors throughout pregnancy predict the development of preeclampsia. STUDY DESIGN: Placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 receptor (sFlt-1) were measured in 2355 women at 10, 18, 26 and 35 weeks gestation. Receiver operator characteristic analysis was used to calculate test characteristics for changes in analytes between time points. Linear mixed-effects models generated slopes of analytes throughout pregnancy, which in turn were used as predictors in adjusted logistic regression models. RESULT: Changes in analytes yielded positive predictive values of 9 to 19% and negative predictive values of 93 to 97%. Individuals with lowest quartile slopes in PlGF had sixfold greater odds (95% confidence interval (CI): 3.5, 10.2) of preeclampsia compared with individuals in the highest quartile. With respect to sFlt-1, the highest quartile had 5.1 times greater odds (95% CI: 3.1, 8.4) than the lowest quartile. CONCLUSION: Measuring the trend in PlGF and sFlt-1 across pregnancy segregates women at increased risk of preeclampsia. However, changes in these factors throughout pregnancy lack clinically useful predictive power.