OS085. Decreased maternal circulating PLGF is a significant predictor of length of pregnancy in women with hypertensive disorders of pregnancy

Abstract

Diagnosis of the presence of disease and prediction of the rate of progression of disease in women with hypertensive disorders of pregnancy remains a clinical problem. Better methods are needed to determine the magnitude of risk to support patient counseling and clinical management. To investigate whether the level of free PlGF is a significant predictor of length of pregnancy in women with hypertension. In this case-control study a single sample was taken between the 22nd and 34th completed gestational weeks from 130 pregnant women with a final diagnosis of: pre-eclampsia (PE), HELLP-syndrome, superimposed pre-eclampsia (SIPE), chronic hypertension (CHT), gestational hypertension (GHT), and normal healthy pregnancy (Control). Plasma was analysed for PlGF using the Triage® PlGF assay (Alere, San Diego). A positive PlGF test was defined as below the 5th centile of normal healthy pregnancy. Hazard ratios for length-of-pregnancy were calculated for a positive PlGF test in a multivariate Cox proportional hazards model adjusting for two covariates, the gestational age at sample collection and a final diagnosis of proteinuric hypertension (PE, HELLP, and SIPE). Median PlGF concentration was significantly lower in women with hypertension than in controls. Women with proteinuric hypertension had the lowest levels of PlGF. A positive PlGF test predicted delivery before 35 weeks in 93.7% women, and delivery before 37 weeks in 90.5% women. A positive PlGF test was associated with a significantly higher risk of imminent delivery. PlGF was a significant and independent predictor of women destined to deliver early because of maternal or fetal complication (adjusted Hazard Ratio of 3.43, 95%CI of 1.97 to 5.98). A positive PlGF test is significant predictor of length of pregnancy, independent of other diagnostic criteria. PlGF has the potential to identify increased risk without the limitation of non-specificity which exists with other diagnostic parameters.