Table 1.
General characteristics of 9 eligible studies contained in this meta-analysis.
| Study name | Country | Ethnicity | Methods | Case selection | Source of control | Sample Size Case/Control | Polymorphisms studied |
| Haggerty, 2005 | USA | EuropeanAfrican American | TaqMan | 1. SBP/DBP > 140/90 mmHg2. Proteinuria > 300 mg/24 h or protein/creatinine ratio >0.33. Hyperuricemia | 1. Normotensive2. No proteinuria or hyperuricemia during pregnancy | 130/46220/199 | IL-10 -819 C/T |
| Kamali, 2006 | Iran | Asian | ASO-PCR/PCR-RFLP | National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy National High Blood Pressure | 1. At least two successful deliveries2. Without any history of PE | 134/164 | IL-10 -819 C/T, IL-10 -592A/C |
| Mirahmadian, 2008 | Iran | Asian | PCR-SSP | National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy | 1. Normal laboratory examination2. No clinical signs and symptoms of PE | 260/100 | IL-10 -819 C/T, IL-10 -592A/C |
| de Lima, 2009 | Brazil | South American | PCR-SSP | National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy | 1. Normotensive in previous pregnancy2. At least one successful pregnancy without any maternal or fetal disorder | 92/101 | IL-10 -819 C/T, IL-10 -592A/C |
| Sowmya, 2014 | India | South-Asian | ARMS-PCR | 1. SBP/DBP >130/90 mm Hg2. New onset of proteinuria > 2 + dipstick | More than 20 weeks pregnancy with normal blood pressure, fetal growth and physiological normalities | 120/120 | IL-10 -819 C/T, IL-10 -592A/C |
| Song, 2015 | China | Asian | PCR-RFLP | 1. SBP/DBP ≥ 140/90 mm Hg2. Proteinuria ≥ 300 mg/24 h or 2+ | 1. More than 20 wks pregnant women2. No history of chronic hypertension, renal, autoimmune, metabolic or cardiovascular disease | 155/201 | IL-10 -819 C/T, IL-10 -592A/C |
| Liu, 2015 | China | Asian | PCR-RFLP | 1. SBP/DBP ≥ 140/90 mm Hg2. Proteinuria | Normal pregnant women in the same period | 177/182 | IL-10 -819 C/T |
| Fan, 2017 | China | Asian | PCR-RFLP | 1. SBP/DBP ≥140/90 mm Hg2. Proteinuria ≥300 mg/24 h | 1. More than 20 wks pregnant women2. No history of chronic hypertension, cardiovascular disease, end-stage liver or renal diseases, or diabetes | 142/260 | IL-10 -592A/C |
| Raguema, 2018 | Tunisia | African | TaqMan | 1. SBP/DBP ≥140/90 mm Hg2. Proteinuria ≥300 mg/24 h or 2+ | 1. Age-matched with cases and from the same region2. No personal or family history of hypertension and PE | 345/300 | IL-10 -819 C/T, IL-10 -592A/C |