Urinary placental growth factor differentiates the hypertensive disorders of pregnancy

The aim of this study was to evaluate the discriminating capacity of urinary placental growth factor (uPlGF) for different hypertensive diseases of pregnancy during the third trimester. A prospective descriptive case-control study was conducted in an urban tertiary referral hospital and district general hospital, Sydney South West Area Health Service, Australia. Inpatients and outpatients with and without hypertension in the third trimester were recruited. Eligible patients provided a urine sample for protein, creatinine and a uPlGF level by ELISA. Patients were categorised into clinical hypertensive groups based on the diagnostic criteria of SOMANZ. Eighty-eight women were evaluated; 41 had hypertension (15 pre-eclampsia; 13 gestational hypertension; eight chronic hypertension; five pre-eclampsia superimposed on chronic hypertension) and 47 women without hypertension as the control group. There was a significant difference in uPlGF levels between the pre-eclamptic group (median 2.56 IQR 1.12-4.51) and the normotensive controls (median 13.18 IQR 5.95-31.39) (P < 0.0001); the gestational hypertensive group (median 3.74 IQR 2.49-4.91) and the normotensive group (median 13.18 IQR 5.95-31.39) (P = 0.002) and for a subgroup comparison of placental-mediated hypertension (median 2.75 IQR 1.38-4.82) versus non-placental-mediated hypertensives (median 6.96 IQR 3.87-12.54) (P = 0.007). Urinary placental growth factor is a simple non-invasive test, which is discriminatory for pre-eclampsia in the third trimester of pregnancy. Results from this study indicate that it may be discriminatory for hypertension related to placental dysfunction (pre-eclampsia and gestational hypertension) when compared with hypertension unrelated to placental function. Further work is required to assess the ability to detect hypertensive diseases before they are clinically apparent.