Maternal Mercury Exposure and Hypertensive Disorders of Pregnancy: A Systematic Review

Abstract

Objective The present review aimed to synthesize the evidence regarding mercury (Hg) exposure and hypertensive disorders of pregnancy (HDP).

Data Sources The PubMed, BVS/LILACS, SciELO and UFRJ's Pantheon Digital Library databases were systematically searched through June 2021.

Study Selection Observational analytical articles, written in English, Spanish, or Portuguese, without time restriction.

Data Collection We followed the PICOS strategy, and the methodological quality was assessed using the Downs and Black checklist.

Data Synthesis We retrieved 77 articles, of which 6 met the review criteria. They comprised 4,848 participants, of which 809 (16.7%) had HDP and 4,724 (97.4%) were environmentally exposed to Hg (fish consumption and dental amalgam). Mercury biomarkers evaluated were blood (four studies) and urine (two studies). Two studies found a positive association between Hg and HDP in the group with more exposure, and the other four did not present it. The quality assessment revealed three satisfactory and three good-rated studies (mean: 19.3 ± 1.6 out 28 points). The absence or no proper adjustment for negative confounding factor, such as fish consumption, was observed in five studies.

Conclusion We retrieved only six studies, although Hg is a widespread toxic metal and pregnancy is a period of heightened susceptibility to environmental threats and cardiovascular risk. Overall, our review showed mixed results, with two studies reporting a positive association in the group with more exposure. However, due to the importance of the subject, additional studies are needed to elucidate the effects of Hg on HDP, with particular attention to adjusting negative confounding.

Resumo

Objetivo A presente revisão busca sintetizar as evidências em relação à exposição ao mercúrio (Hg) e os distúrbios hipertensivos da gestação (DHG).

Fontes Dos Dados Os bancos de dados PubMed, BVS/LILACS, SciELO e a Biblioteca Digital da UFRJ Pantheon foram sistematicamente pesquisadas durante junho de 2021.

Seleção de estudos Artigos observacionais analíticos, escritos em inglês, espanhol ou português, sem restrição temporal.

Coleta de Dados A estratégia PICOS foi seguida e a qualidade metodológica foi avaliada usando o checklist Downs and Black.

Síntese de dados Foram encontrados 77 artigos, dos quais 6 atenderam aos critérios da revisão. Foram 4.848 participantes, dos quais 80 (16,7%) tinham DHG e 4.724 (97,4%) estavam expostos ambientalmente ao Hg (consumo de peixe e amálgama dental). Os biomarcadores de mercúrio avaliados foram sangue (quatro estudos) e urina (dois estudos). Dois estudos encontraram associação positiva entre Hg e DHG no grupo com maior exposição e os outros quatro não a apresentaram. A avaliação de qualidade metodológica revelou 3 estudos satisfatórios e 3 bons (média: 19,3 ± 1,6 em 28 pontos). A ausência ou não de ajuste adequado para fator de confusão negativo, como consumo de pescado, foi observada em cinco estudos.

Conclusão Recuperamos apenas seis estudos, embora o Hg seja um metal tóxico generalizado e a gravidez seja um período de maior suscetibilidade a ameaças ambientais e risco cardiovascular. No geral, nossa revisão mostrou resultados mistos, com dois estudos relatando associação positiva no grupo com maior exposição. No entanto, devido à importância do assunto, estudos adicionais são necessários para elucidar os efeitos do Hg sobre DHG, com atenção especial ao ajuste de confundimento negativo.

Keywords

mercury - pregnancy-induced hypertension - preeclampsia - eclampsia and gestational hypertension

Palavras-chave

mercúrio - hipertensão induzida pela gestação - pré-eclâmpsia - eclâmpsia e hipertensão gestacional

Publication History

Received: 27 June 2022

Accepted: 26 September 2022

Article published online:
29 December 2022

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