Prevenção da pré-eclâmpsia: o que as evidências apontam?

Abstract

Preeclampsia is a multifactorial and multisystemic disease specific to pregnancy diagnosed by the presence of hypertension associated with proteinuria manifested in a previously normotensive pregnant woman after the 20th week of gestation. However, throughout the world, the evidence regarding treatments for the prevention of preeclampsia is a matter of much controversy. Therefore, the objective of this review is to map and evaluate the scientific evidence on alternative treatments for prevention of preeclampsia found in the scientific literature. This research was structured in two phases, the first a scoping review aiming to map in the scientific literature following the PRISMA-ScR protocol; the second, a systematic review with meta-analysis of the most frequently researched treatments for the prevention of PE, following the PRISMA protocol, and a risk of bias analysis using Cochrane's Risk of Bias 2.0 tool for randomized clinical trials. To identify relevant studies, Pubmed, Scopus, LILACS, Embase, and Bireme databases were searched without year restriction. The search algorithm was performed using the PICO (patient, interventions, control, and outcome) strategy. In total, 33 clinical trials were included in the scoping review, and 22 of these articles were included in the systematic review with meta-analysis. In the scoping review, the diversity of interventions and doses makes it clear that there is still no ideal therapy for PE prophylaxis. In the systematic review, meta-analyses were performed with aspirin, calcium, and the antioxidants (vitamins C and E), in addition to the risk of bias analysis of the clinical trials. The meta-analysis of aspirin included 9 articles and their corresponding combined effects were OR = 0.70 (95% CI: 0.54 - 0.91), however, the methodological quality of these studies was not good, presenting high risk of bias in 6/9 studies. In the meta-analysis of calcium, 6 articles were included OR= 0.64 (95% CI: 0.44, 0.93) and only 1 study has a good methodological quality. And in the analysis of vitamin C and E, 7 clinical trials OR = 0.99 (95% CI: 0.85, 1.15) were included, which 3/7 clinical trials have good methodological quality. Overall, none of the interventions were able to generate conclusive evidence that they are effective treatments for preeclampsia.