Table 1 Study characteristics of oxidative stress (OS) markers of included studies
Name of oxidative stress (OS) markers | Author/Reference | Study design | Sample | Optimal cut-off | Control type | n (Control) | PE type | n (PE) | GA at sampling | Exclusion criteria |
|---|---|---|---|---|---|---|---|---|---|---|
Ischemia-modified albumin (IMA) | Ustun et al. [13] | Case–control | Serum |  > 0.31 ABSU or ng/ml | Normotensive, non-smoker | 18 | EOPE and LOPE are mixed | 36 | 32–38 weeks | Multiple pregnancy, chronic hypertension, renal disease, diabetes mellitus, other pre-existing disorders, the early history of preeclampsia, HELLP syndrome, immunosuppression, or a history of using illicit drugs |
Vyakaranam et al. [14] | Case–control | Serum |  > 38.33 ng/mL | Normotensive | 19 | EOPE and LOPE are mixed | 19 |  ≥ 32 weeks | History of pregnancy complications, twin pregnancy, previous pregnancy with hypertensive disorders, pre-existing chronic conditions including diabetes mellitus, chronic hypertension, ischemic heart disease, peripheral vascular diseases | |
Bambrana et al. [6] | Case–control | Serum | NA | Normotensive, non-smoker | 57 | NA | 57 | 30–39 weeks before delivery and after delivery within 48 h | Pre-existing renal disease, thyroid disorders, chronic hypertensive disorder, gestational diabetes mellitus, epilepsy, hypertensive encephalopathy, heart disease, multiple pregnancies, fetal anatomical anomalies | |
Malondialdehyde (MDA) | Rani et al. [22] | Case–control | Placental tissue | 6.5 nmol/g | Normotensive | 30 | EOPE and LOPE are mixed | 30 | Within 20 min of delivery | Chorioamnionitis, chronic hypertension, renal disease, cardiovascular disease, active asthma, thyroid disorders, and a history of seizures |
Bambrana et al. [6] | Case–control | Serum | NA | Normotensive, non-smoker | 57 | NA | 57 | 30–39 weeks before delivery and after delivery within 48 h | Pre-existing renal disease, thyroid disorders, chronic hypertensive disorder, gestational diabetes mellitus, epilepsy, hypertensive encephalopathy, heart disease, numerous pregnancies, fetal anatomical anomalies | |
Shaker et al. [23] | Case–control | Placental tissue | 0.14 nmol/mg | Normotensive | 25 | EOPE and LOPE are mixed | 25 | Immediately after delivery | Pre-existing hypertension before 20 weeks gestation and women with pregnancy complications including diabetes mellitus, peripheral vascular disease, chronic renal disease, multifetal gestation, or major fetal anomalies | |
Uric acid (UA) | Nikolic et al. [3] | Case–control | Serum |  > 242 μmol/L | Normotensive | 60 | EOPE and LOPE are mixed | 32 |  ≥ 24 weeks | Multifetal gestation, abnormal fetal morphology, pre-existing diseases, and gestational age prior to 24 weeks |
Bambrana et al. [6] | Case–control | Serum | NA | Normotensive, non-smoker | 57 | NA | 57 | 30–39 weeks before delivery and after delivery within 48 h | Pre-existing renal disease, thyroid disorders, chronic hypertensive disorder, gestational diabetes, epilepsy, hypertensive encephalopathy, heart disease, numerous pregnancies, fetal anatomical anomalies | |
Vyakaranam et al. [15] | Case–control | Serum |  > 4.9 mg/dL | Normotensive | 31 | EOPE and LOPE are mixed | 30 |  > 32 weeks | Repeated abortions, previous pregnancy complications, twin pregnancy, pre-existing medical disorders: diabetes mellitus, chronic hypertension, renal diseases, cardiovascular diseases, thyroid disorders, and liver disease |