Performance of the sFLT-1 / PLGF Ratio in the Diagnosis of Preeclampsia in Four Hospitals in Brazzaville (Republic of Congo)

Abstract

Preeclampsia is a serious obstetric situation, responsible for high maternal and perinatal morbidity and mortality. Its diagnosis is clinical and biological, with confirmation either by proteinuria on the urine dipstick or by 24-hour proteinuria constituting the gold standard. Current revisions to the definition of preeclampsia tend to free themselves from reliance on proteinuria for diagnosis. They are oriented towards a broader model where the involvement of a target organ concomitant with gestational hypertension is sufficient to make the diagnosis of preeclampsia. Late positivity of proteinuria after the onset of arterial hypertension (HTA) has been reported, contrasting with the precocity of angiogenic factors such as soluble Fms tyrosine kinase type 1 (sFlt-1) and placental growth factor (PlGF). Objective. To evaluate the performance of the sFLT1/PLGF ratio in the diagnosis of preeclampsia. Methods. Cross-sectional multicenter analytical study conducted from October 17 to December 17, 2020 including hypertensive pregnant women, treated or not, with more than 20 weeks of amenorrhea. These all benefited from the Elisa assay of sFLT-1 and PlGF after carrying out the proteinuria on the urine dipstick during the consultation. Preeclampsia was defined by the double positivity of proteinuria on the urine dipstick associated with high blood pressure (Systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg). SPSS software was used for statistical analysis and calculation of performance indices (Se; Sp; PPV; NPV; Youden “J” index, AUC). The p-value of the probability was considered significant for a value < 0.05. Results. Pregnant women were mostly multiparous with a median age of 31 years (24-35). Preeclampsia was noted in 69.2% of cases. sFLT-1 was significantly higher in preeclamptic pregnant women (409±18.9 vs 194.6±12.9; p<0.05). No significant difference was noted for PlGF (11.9 vs 13.6; p< 0.05). The sFlt1/PlGF ratio was higher in case of preeclampsia (39.3 vs 14.6; p< 0.05). The threshold for the sFlt-/PlGF ratio retained was 18.5 (Se=86.4%; Sp=84.6%; PPV=90.5%; NPV=78.6%; J = 0.7; AUC =0.9). Conclusion. The sFlt-1/PlGF ratio was effective in the diagnosis of preeclampsia.