OP13.05: Assessment of the angiogenic ratio versus glycosylated fibronectin in predicting adverse maternal outcome in women with suspected pre‐eclampsia

To compare inter-manufacturer angiogenic ratio rule-in/rule-out predictive performance for composite adverse maternal and neonatal outcome versus a point-of-care (PoC) test in East Asian women presenting with a singleton pregnancy after 20 weeks of gestation with hypertension ± clinical features of pre-eclampsia (PE). Pro- and anti-angiogenic levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt1) were measured using the Roche Cobas e411, BRAHMS Kryptor, Ningbo-Aucheer Imagin1800 immunoassays in 225 maternal serum samples, 67 of whom subsequently developed PE. Glycosylated fibronectin (GlyFn) levels were determined using the LumellaTM PE PoC test. Women with PE at presentation were excluded. PE was diagnosed according to the ISSHP 2021 classification. The sFlt1:PlGF ratio was stratified as “High” or “Low” using assay specific thresholds equivalent to a Roche sFlt1:PlGF ratio of 38. GlyFn was classified as “High” or “Low” using a GlyFn level of 263 ug/ml. Adverse outcome was defined as PE with or without severe features, maternal death, maternal ICU admission, postpartum hemorrhage (>500ml). Negative predictive value (NPV) to rule-out composite adverse outcome and positive predictive value (PPV) to rule-in composite adverse outcome at time of presentation were determined. 95 pregnancies had an adverse maternal outcome. NPV of “Low” Roche, Kryptor, and Ningbo-Aucheer sFlt-1:PlGF ratio and “Low” GlyFn to rule-out adverse outcomes were respectively 72.5%, 71.5%, 72.7%, 59.2%. Corresponding manufacturers PPV of a “High” sFlt-1:PlGF ratio or GlyFn to rule-in adverse outcomes were 67.5%, 70.3%, 63.4%, 46.4%. NPV and PPV of different assay manufacturers sFlt-1:PlGF ratio were similar once standardised to a common equivalent threshold and higher than those of GlyFn.