The ratio of the maternal plasma angiogenic factors soluble Fms-kinase 1 (sFlt-1) and placental growth factor (PlGF) is a novel diagnostic tool for preeclampsia (PE), with a value <38 predicting short-term absence of PE in women in whom the syndrome is suspected clinically. The clinical implication of a single determination below the sFlt-1/PlGF ratio of 38 beyond 1 week remains to be established. We therefore assessed the evolution of the sFlt-1/PlGF ratio in patients suspected of PE on clinical grounds.Design and method:
In this ongoing study, using the Elecsys assays (Roche Diagnostics), the sFlt:1/PlGF ratio was determined at >2 time points in 39 pregnant women with suspected PE (new onset or aggravation of hypertension and/or proteinuria; renal insufficiency [serum creatinine >100 μmol/l]; neurological complications [severe headache, hyperreflexia, persistent visual scotoma, blindness, stroke, seizures]; severe edema or HELLP symptoms [right upper quadrant/epigastric abdominal pain; elevated transaminases; thrombocytopenia; hemolysis]).Results:
In 39 patients with singleton pregnancies, aged 23–44 years and a median pregnancy duration of 28 weeks (range 20–37 weeks), the ratio of 6 (range 2–34) at inclusion remained constant for up to 100 days in patients with an underlying disease, including hypertension, proteinuria and other renal disease such as systemic lupus erythematosus, despite the fact that their protein-to-creatinine ratio and blood pressure often rose. In contrast, in patients with clinical PE or in whom (superimposed) PE eventually occurred based on clinical grounds (hypertension and proteinuria) the ratio of 67 (range 5–277) at inclusion rapidly increased further, often doubling every additional week. Of these patients with clinical PE 7 women had a ratio <38, nonetheless pregnancy in 6 of them could be prolonged for over 15 days or they delivered at term with mild features.Conclusions:
Our findings indicate that patients without an angiogenic imbalance, i.e. an Elecsys sFlt-1/PlGF ratio of 38 and lower, carry a small risk of adverse events despite being diagnosed with PE on clinical grounds. The latter underscores the importance to highlight angiogenic imbalanced PE rather than the heterogeneous and less specific clinical diagnosis in future studies and clinical management.