Cadmium exposure and Hypertensive Disorders of Pregnancy: a systematic review

ABSTRACT

Hypertensive Disorders of Pregnancy (HDP) are one of the main causes of maternal morbimortality. Strong evidence point to an association between cadmium and hypertension in the general population, but not HDP. A systematic review was carried out to investigate this potential relationship, following PRISMA guidelines, in the BVS/LILACS, PubMed/MEDLINE, and SciELO databases and a repository (University of São Paulo – USP) until August 2021. The methodological quality was assessed using the Downs and Black checklist. Nineteen articles were selected, thirteen of which were case-control, four were cohorts, and two were cross-sectional. A total of 11.451 participants were evaluated, 1.445 (12.6%) with HDP, and of these 1.071 (74.1%) with preeclampsia. The inadequate adjustment for confounding was observed in eleven studies. Out of the seven studies considered good methodological quality, four reported a positive association, and three did not observe it. In contrast, only one observed a mean difference, which was higher in HDP. The inconsistency of the results was attributed to the methodological differences and inadequate adjustment for confounding. As cadmium is a toxic metal that can induce an increase in oxidative stress, which plays an essential role in the pathophysiology of HDP, additional studies are needed to elucidate this association.

KEYWORDS
Cadmium; Hypertension, pregnancy-induced; Pre-eclampsia; Eclampsia