Selenium, Zinc, and Copper in Preeclampsia: Research Trends, Direction of Evidence, and Knowledge Gaps

Abstrak

Selenium (Se), zinc (Zn), and copper (Cu) are involved in antioxidant defence, endothelial regulation, and placental function, but their circulating concentrations in preeclampsia remain inconsistently reported. To characterize publication trends, methodological orientation, direction of observational evidence, and priority research gaps for maternal circulating Se, Zn, and Cu in preeclampsia. Scopus and PubMed were searched through 30 July 2026. After investigator-resolved deduplication in Rayyan, 280 unique records formed the bibliometric corpus. Protocol 1 included observational human studies in pregnant women, with preeclampsia as the primary outcome, measuring Se, Zn, or Cu in maternal serum, plasma, leukocytes, or erythrocytes. Evidence mapping was restricted to 2006-2025. Human observational studies dominated the corpus (216/280; 77.1%), followed by experimental/basic science studies (21; 7.5%), systematic reviews/meta-analyses (14; 5.0%), narrative reviews (11; 3.9%), intervention studies (11; 3.9%), and other formats (7; 2.5%). Forty-eight reports met Protocol 1; 33 were eligible within the 20-year window and 32 full texts, representing 30 unique populations, were included. Only five populations used prospective or prediagnostic sampling. Selenium showed the most consistent inverse pattern. Zinc was generally lower but heterogeneous, whereas copper findings were bidirectional; the Cu/Zn ratio was consistently higher in three studies. The field is association-rich but temporality-poor. Priorities are serial early-pregnancy cohorts, preeclampsia-phenotype stratification, adjustment for nutritional and inflammatory factors, matrix-specific analytical standardization, and external validation before biomarker-guided interventions.

Kata kunci

• selenium
• zinc
• copper
• preeclampsia
• bibliometric analysis
• evidence mapping
• oxidative stress