Objective: The outcome of preeclampsia is difficult to predict. Laboratory markers such as soluble fms-like tyrosine kinase (sFlt-1) and placental growth factor (PlGF) are thought to be predictive factors. A 2012 study by Verlohren et al. evaluated cut-off values for assessing time to delivery in patients with elevated sFlt-1/PlGF ratios. The present study aimed to evaluate findings in patients with elevated sFlt-1/PlGF ratios who gave birth at Kepler University Hospital in Linz, Austria. The hypothesis was tested, that our patients show longer pregnancy duration despite elevated sFlt-1/PlGF ratios.
Study design: This retrospective data analysis included all patients with sFlt-1/PlGF ratios above the established cut-off values between January 2014 and October 2017. Two groups were analyzed relative to gestational age and were matched with healthy controls: 24 + 0 to 33 + 6 gestational weeks, sFlt-1/PlGF ratio >655.2; and 34 + 0 to 36 + 6 gestational weeks, sFlt-1/PlGF ratio >201.
Main outcome measures: sFlt-1/PlGF ratio and time to delivery correlation.
Results: In the <34-week group, 43.2% of the patients delivered beyond 48 h, with a mean sFlt-1/PlGF ratio of 885.06, showing a significantly lower sFlt-1/PlGF ratio than patients who delivered within 2 days (P = 0.04). In the >34-week group, 66.7% were still pregnant after 48 h, with a mean sFlt-1/PlGF ratio of 273.7.
Conclusion: The sFlt-1/PlGF ratio appears to be a powerful tool for diagnosing and predicting preeclampsia. However, the data do not confirm the cut-off values described earlier, with longer pregnancy durations in this group of patients.
Keywords: Placental growth factor; Preeclampsia; Soluble fms-like tyrosine kinase-1; Time to delivery; sFlt-1/PlGF.
Copyright © 2020 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.