Exposição ao cádmio e Síndromes Hipertensivas da Gestação: uma revisão sistemática / Cadmium exposure and Hypertensive Disorders of Pregnancy: a systematic review

RESUMO As Síndromes Hipertensivas da Gestação (SHG) são uma das principais causas de morbimortalidade materna. Evidências crescentes indicam a associação entre a exposição ao cádmio e a hipertensão arterial na população em geral, mas não as SHG. Afim de investigar esse tema, realizou-se uma revisão sistemática seguindo as diretrizes PRISMA, nas bases de dados BVS/Lilacs, PubMed/Medline e SciELO e no repositório da Universidade de São Paulo (USP) até agosto de 2021. A qualidade metodológica foi avaliada pelo checklist Downs and Black. Selecionaram-se dezenove artigos, sendo treze caso-controle, quatro coortes e dois seccionais. No total, 11.451 participantes foram avaliadas, sendo 1.445 (12,6%) com SHG e, destas, 1.071 (74,1%) com pré-eclâmpsia. Observou-se o ajuste inadequado para confundimento em onze estudos. Dos sete estudos considerados de boa qualidade metodológica, quatro relataram associação positiva e três não a observaram, enquanto somente um estudo observou diferença de média, que foi maior nas gestantes com SHG. Atribuiu-se a divergência dos resultados às diferenças metodológicas e ao ajuste inadequado para os fatores de confusão. Como o cádmio é um metal tóxico que pode levar ao aumento do estresse oxidativo, que desempenha papel importante na fisiopatologia das SHG, estudos adicionais são necessários para elucidar esta associação.

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.

Risk factors for preeclampsia and eclampsia in Sidama region, southern Ethiopia: a nested case-control study

Introduction: though Ethiopia has made a significant improvement in the reduction of maternal mortality, the high burden of preeclampsia remains a concern in the Sidama region of southern Ethiopia. This study aimed to determine the risk factors for preeclampsia and eclampsia in the Sidama region of southern Ethiopia. Methods: a nested case-control study was conducted from August 8, 2019, to October 1, 2020 in the Sidama region. Two-stage sampling techniques were used to recruit study participants. First, seven of the 13 public hospitals were selected using a random sampling technique. Second, cases and controls were selected from a cohort of pregnant women enrolled at ≥20 weeks of gestation up until the 37th week. Data were collected in a face-to-face interview using a locally translated and validated tool. Binary logistic regression analysis was used to identify risk factors for preeclampsia and eclampsia Results: of the planned sample size of 816 women, we enrolled 808 (404 cases and 404 controls). Of the 404 cases, (59.40%, 240/404) had preeclampsia without severity features, (30.94%, 125/404) had preeclampsia with severity features, and (9.65%, 39/404) had convulsions. After controlling for confounders, women having a low wealth status were 98% [AOR: 1.98, 95%CI: 1.34-2.92] at higher risk for preeclampsia and eclampsia compared to women having a high wealth status. Women who had early neonatal deaths were 5 times more likely to be developed preeclampsia and eclampsia than women who did not have early neonatal deaths [AOR: 5.09, 95%CI: 1.69-9.36]. Women who did not attend school were three times more likely to develop preeclampsia and eclampsia [AOR: 3.00, 95% CI: 1.10-8.19] compared to women who attended college/university. Conclusion: in this study, a higher risk for preeclampsia and eclampsia was observed among women with low wealth status, women who had early neonatal deaths and women who did not attend school. Some of these factors could be positively influenced by educational interventions. Maternal and child health providers should screen pregnant women at risk for preeclampsia and eclampsia using these factors. Findings of this study will provide epidemiological evidence for policy makers and implementers to reduce the occurrence of preeclampsia and eclampsia.

Emergências Hipertensivas na Gravidez / Hypertensive Emergencies in Pregnancy

As síndromes hipertensivas são as complicações mais frequentes na gestação e constituem, no Brasil, a primeira causa de morte materna, principalmente quando se instalam nas suas formas graves, como a eclampsia e a síndrome HELLP. São ainda responsáveis por altas taxas de mortalidade perinatal, prematuridade e restrição de crescimento fetal. Compreendem duas entidades distintas: a hipertensão arterial crônica e a pré-eclâmpsia. Eventualmente, a pré-eclâmpsia pode instalar-se em uma gestante hipertensa crônica, quadro denominado pré-eclâmpsia superajuntada. A pré-eclâmpsia tem etiologia desconhecida. Sua fisiopatologia relacionase com diminuição da perfusão placentária. O fluxo útero-placentário está diminuído levando ao quadro de insuficiência placentária. São fatores predisponentes as gestantes com hipertensão arterial, diabéticas, com doenças autoimunes, doenças do parênquima renal e aquelas com aumento da massa placentária como a gestação múltipla, gestação molar etc. Uma vez diagnosticada a doença, o objetivo do tratamento é a prevenção das complicações materno-fetais como o descolamento prematuro da placenta, acidente vascular cerebral, edema agudo de pulmão, insuficiência renal e o agravamento do quadro clínico para pré-eclâmpsia grave, síndrome HELLP e eclampsia; para o lado fetal, o parto prematuro e o desconforto respiratório do recém-nascido. O sulfato de magnésio é a droga de escolha para o controle das convulsões eclâmpticas. O melhor tratamento para pré- eclâmpsia continua sendo o pré- natal correto, diagnóstico e tratamento clínico precoce e o adequado momento para a interrupção da gestação, que é o tratamento definitivo.

Hypertension during pregnancy is the first cause of maternal mortality in Brazil, mainly in the severe stages like eclampsia and HELLP syndrome and is also responsible for the high incidence of fetal mortality, preterm birth and fetal growth restriction. There are two types of hypertension in pregnancy: the chronic hypertension and preeclampsia. The last one can superimpose upon chronic hypertension and then is named superimposed preeclampsia. Preeclampsia refers to a syndrome of a new onset hypertension and proteinuria after 20 weeks of gestation in a previously normotensive woman. The risk factors to development of preeclampsia are: hypertension, diabetes, autoimmune disease, kidney disease, multiple gestations and trophoblastic disease. Preeclampsia has an unknown etiology, although the physiopathology is the low uteroplacental blood flow and placental underperfusion. The decision to treat using antihypertensive therapy has a well established benefit in reducing severe cases of fetal and maternal complications, such as: placental abruption, cerebral hemorrhage, pulmonary edema, renal abnormality, severe preeclampsia, HELLP syndrome and eclampsia. It also prevents to the fetus preterm birth and fetal chest discomfort. Magnesium sulfate is the drug of choice to control the seizures of eclampsia. Finally, the best treatment to preeclampsia and other types of hypertension in pregnancy is the early diagnosis, treatment and the correct moment to delivery, which is the definitive treatment.