Data collection and outcome measures
Maternal characteristics including age, parity, height, weight, the
estimated date of confinement (EDC), gestational age (GA) at the time of
blood sampling and the diagnosis PE were collected from the medical
record. Blood pressure was measured at each visit of routine antenatal
care by the standard protocol. The diagnosis of hypertensive disorders
was made after delivery and was classified into gestational hypertension
(GH), PE, chronic hypertension (chrHBP) and chrHBP with PE according to
the standard of the American College of Obstetrics and
Gynecology[1]. PE was stratified into early- and late-onset
according to the occurrence before or after 34+0 weeks of gestation,
respectively. Patients with any forms of HELLP syndrome (hemolysis,
elevated liver enzyme, low platelet) and eclampsia were reclassified as
PE. All the patients were managed by the standard clinical practice in
our center regardless of the results of sFlt/PlGF ratios.