Retrospective evaluation of established cut-off values for the sFlt-1/PlGF ratio for predicting imminent delivery in preeclampsia patients.

Abstract

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. 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. sFlt-1/PlGF ratio and time to delivery correlation. In the <34-week group, 43.2% of the patients delivered beyond 48h, with a mean sFlt-1/PlGF ratio of 885.06, showing a significantly lower sFlt-1/PlGF ratio than patients who delivered within 2days (P=0.04). In the >34-week group, 66.7% were still pregnant after 48h, with a mean sFlt-1/PlGF ratio of 273.7. 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.