Diagnostic and predictive accuracy of placental growth factor in suspected pre-eclampsia

The diagnosis of preeclampsia can be difficult with considerable uncertainty when the presenting features are borderline. Moreover underlying medical conditions may obscure or simulate the onset of pre-eclampsia. There is a clinical need to be able to diagnose, more accurately, those forms of the disease that are likely to progress to an adverse fetal or maternal outcome. Maternal circulating placental growth factor (PIGF) concentrations are decreased in these women, in correlation with disease severity and gestational age of onset. In this study its diagnostic performance was evaluated with an accurate, point of care test. The PELICAN study was a prospective observational cohort study, in seven maternity units in the British Isles. 625 women presenting between 20+0 and 40+6 weeks gestation with suspected preeclampsia were recruited, excluding those already diagnosed with preeclampsia. PIGF was measured (Alere Triage® PIGF test) in the enrolment sample after all participants had delivered so that clinical decisions were not affected by its results. ISSHP definitions of hypertensive disease were assigned, blinded to PIGF values. Analysis was conducted to assess diagnostic accuracy of the enrolment PIGF level for placental dysfunction requiring delivery within 14days. In women who presented before 35 week's gestation the PIGF test predicted placental dysfunction, that required deliverywithin the next 14days, with the following characteristics: sensitivity 0.95 (0.86-0.98); specificity 0.56 [0.49-0.63); NPV 0.97 (0.92-0.99); PPV0.42 (0.35-0.51).

PIGF is a strong predictor of time-to-delivery and may be an independent and complementary tool to assist in diagnosis and risk stratification of pregnancies complicated by placental dysfunction. These valuable attributes are to be tested in prospecting randomised double-blind controlled trial.