| First Author, Year (PMID) | Number    of | Inclusion    Criteria for | Additional    Criteria | 
      
        | Sample | Control | PE | Hypertension | Proteinuria | 
      
        | Epiney,2012 [4]
          (22234358) | Secreted | 6 | 4 | SBP    ≥ 160mmHg or DBP ≥ 110mmHg | ≥ 5g/24hr | N/A | 
      
        | Feng,    2012 [39]
          (22414876) | Tissue | 10 | 10 | SBP    ≥ 140 mm Hg or DBP ≥ 90 mm Hg | ≥    0.3 g/24hr or ≥ 2 by dipstick
          measurement | C-section,    epidural
          anesthesia,    age and
          gestational    age matched | 
      
        | Gharesi-Fard,    2010 [40]
          (19954843) | Tissue | 5 | 5 | SBP    ≥ 160mmHg or DBP ≥ 110mmHg on two occasions 6 hrs
          apart | ≥    500mg/24hrs | C-section,    age and gestational
          Age | 
      
        | Jin,    2008 [41]
          (18940332) | Tissue | N/A | 8 | BP    ≥ 140/90 | ≥    300mg/24hrs | C-section,    age, time of
          pregnancy | 
      
        | Kolla,    2012 [42]
          (22570525) | Serum | 6 | 6 | N/A | N/A | Age    and gestational age
          Matched | 
      
        | Lui,    2011 [43]
          (21145106) | Serum | 5 | 5 | SBP    ≥ 160 mmHg or DBP ≥ 110mmHg on 2 occasions at least 6hrs
          apart | ≥    5 g/24h or ≥ 2 by dipstick
          measurement | C-section,    third trimester,
          gestational    age-matched | 
      
        | Ma,    2013 [44]
          (24343450) | Tissue | 1 | 1 | N/A | N/A | C-section,    age, gestational
          Age,    and parity matched | 
      
        | Park,    2011 [45]
          (21646846) | Serum | 5 | 5 | SBP    ≥ 160mmHg or DBP ≥ 110mmHg | ≥    2 by dipstick measurement
          at    least 6hrs apart | C-section, age matched | 
      
        | Shi,    2013 [30]
          (23671712) | Tissue | 4 | 4 | BP    ≥ 160/110 mmHG on two occasions w/in 4 hrs | ≥    2g /24hrs | C-section,    age, gestational
          age,    and parity matched | 
      
        | Shin,    2011 [46]
          (21335933) | Tissue | 10 | 10 | SBP    ≥ 160mmHg or DBP ≥ 90mmHg | ≥    300mg/24hr | C-section, | 
      
        | Wang,    2013 [28]
          (24260401) | Tissue | 20 | 20 | SBP    ≥ 150mmHg or DBP ≥ 110mmHg on 2 occasions in 6 hrs | N/A | N/A | 
      
        | Wang,    2013 [29]
          (24205073) | Tissue | 20 | 20 | SBP    ≥ 150mmHg or DBP ≥ 110mmHg on 2 occasions in 6 hrs | N/A | N/A |