VP50.20: Second and third trimester serum levels of HtrA1 in the prediction of pre‐eclampsia

Altered placental expression of high temperature requirement factor A1 (HtrA1) is implicated in abnormal trophoblastic invasion and endothelial dysfunction in pre-eclampsia (PE). Serum HtrA1 is proposed as a novel biomarker to improve prediction of PE. We aimed to assess serum HtrA1 levels in women who later developed PE compared to controls. This is a case-control study of second and third trimester serum HtrA1 levels in women who later developed preterm and term PE compared to controls. 300 samples were drawn from a prospective observational study of adverse pregnancy outcomes at the Fetal Medicine Research Institute, King's College Hospital, London. HtrA1 levels were determined by enzyme-linked immunosorbent assay (ELISA) by blinded laboratory professionals. HtrA1 values, adjusted for gestational age and maternal characteristics, were compared at each gestational age using one-way analysis of variance (ANOVA), with Dunnett's post-hoc analysis. Women who later developed PE had significantly higher maternal weight and more frequently had PE in a previous pregnancy and chronic hypertension compared to controls. Serum HtrA1 was detectable in the second and third trimesters and increased with increasing gestation in normotensive pregnancies. In PE pregnancies, HtrA1 levels were not significantly different from controls at any gestation (table 1). HtrA1 levels show high variability throughout gestation in all pregnancies and are no different in women who later developed PE compared to controls. VP50.20: Table 1. Second and third trimester serum HtrA1 levels HtrA1 (ng/μL), Median (IQR)