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

Dantas, Aline de Oliveira; Castro, Thiania dos Santos da Silva de; Câmara, Volney de Magalhães; Santos, Aline de Souza Espindola; Asmus, Carmen Ildes Rodrigues Froes; Vianna, Angelica dos Santos

doi:10.1055/s-0042-1760215

Acessibilidade / Reportar erro

Brasil

Revista Brasileira de Ginecologia e Obstetrícia

Español English

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Review Article • Rev Bras Ginecol Obstet 44 (12) • 2022 • https://doi.org/10.1055/s-0042-1760215 copy

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

Exposição materna a mercúrio e distúrbios hipertensivos na gestação: Uma revisão sistemática

Authorship SCIMAGO INSTITUTIONS RANKINGS

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.

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

Author year country	Study characteristics design; number	Characteristics of the participants		Hg assessment			Outcome	Mean difference/ measure of association
Author year country	Study characteristics design; number	Age (Mean: years old)	Ethnicity	Site of exposure (source)	Biological matrix (laboratory technique)	Mercury level	Outcome	Mean difference/ measure of association
Vigeh et al. (2006),²⁰20 Vigeh M, Yokoyama K, Ramezanzadeh F, Dahaghin M, Sakai T, Morita Y, et al. Lead and other trace metals in preeclampsia: a case-control study in Tehran, Iran. Environ Res. 2006;100(02): 268–275. Doi: 10.1016/j.envres.2005.05.005 https://doi.org/10.1016/j.envres.2005.05... Iran	Case-control; n = 396	27	396 NI	Environ	Maternal blood and UBC (ICP-MS)	Maternal blood: PE: 1.35 (0.74); Control: 1.34 (1.19) UBC: PE: 1.69 (1.19) Control: 1.70 (1.33)	PE	Mean difference: no
El-Badry et al. (2018),²⁵25 El-Badry A, Rezk M, El-Sayed H. Mercury-induced oxidative stress may adversely affect pregnancy outcome among dental staff: a cohort study. Int J Occup Environ Med. 2018;9(03):113–119. Doi: 10.15171/ijoem.2018.1181 https://doi.org/10.15171/ijoem.2018.1181... Egypt	Cohort; n = 124	Ex:25.6 NEx: 25.9	124 NI	Environ (fish) Occupat (dentist)	Urine (CVAAS)	Urine 3rd quarter: Ex: 42.8 (13.7); NEx: 7.1 (3.9)	PE	Mean difference: yes; RR_Ex = 3.67 (1.25–10.76)
Bommarito et al. (2019),²¹21 Bommarito PA, Kim SS, Meeker JD, Fry RC, Cantonwine DE, McElrath TF, et al. Urinary trace metals, maternal circulating angiogenic biomarkers, and preeclampsia: a single-contaminant and mixture-based approach. Environ Health. 2019;18(01):63. Doi: 10.1186/s12940-019-0503-5 https://doi.org/10.1186/s12940-019-0503-... USA	Case-control; n = 383	32.7	231 white 57 black 95 NI	Environ	Urine (ICP-MS)	Urine 3rd quarter: PE: 0.50 (0.24, 0.76); Control: 0.51 (0.27, 0.97)	PE	HR unimetal = 0.90 (0.63 - 1.28; p = 0.55); HR multimetal As, Hg, Sn = 0.75 (0.39–1.46; p = 0.40)
Liu et al. (2019),²²22 Liu T, Zhang M, Guallar E, Wang G, Hong X, Wang X, et al. Trace minerals, heavy metals, and preeclampsia: findings from the Boston Birth Cohort. J Am Heart Assoc. 2019;8(16):e012436. Doi: 10.1161/JAHA.119.012436 https://doi.org/10.1161/JAHA.119.012436... USA	Cohort; n = 1.274	27.99	739 black 535 NI	Environ	Maternal red blood cells (ICP-MS)	Maternal blood: PE: 2.1 (1.0–4.7); Control: 2.0 (1.0–3.6)	PE	Mean difference: no; Prevalence ratio = 1,03 (0.88–1.20; p = 0.71)
Louopou et al. (2020),²³23 Louopou RC, Trottier H, Arbuckle TE, Fraser WD. Dental amalgams and risk of gestational hypertension in the MIREC study. Pregnancy Hypertens. 2020;21:84–89. Doi: 10.1016/j.preghy.2020.04.015 https://doi.org/10.1016/j.preghy.2020.04... Canada	Cohort; n = 1.817	31.86	1.563 white 254 NI	Environ (fish, amalgam)	Maternal blood (ICP-MS)	Maternal blood 1st trimester: zero amalgams: 0.58 1 to 4 amalgams: 0.74 ≥ 5 amalgams: 0.90	GH	Mean difference: yes; aOR = 1.31 (0.92, 1.85) < 5 dental amalgams group; aOR = 1.32 (0.86, 2.04) ≥ 5 dental amalgams group
Wang et al. (2020),²⁴24 Wang Y,Wang K, Han T, Zhang P, Chen X,WuW, et al. Exposure to multiple metals and prevalence for preeclampsia in Taiyuan, China. Environ Int. 2020;145:106098. Doi: 10.1016/j.envint.2020.106098 https://doi.org/10.1016/j.envint.2020.10... China	Case-control; n = 854	20–30	854 NI	Environ	Maternal blood (ICP-MS)	Maternal blood: PE: 1.52 (0.97–2.36); Control: 1.49 (0.96–2.08)	PE	aOR = 1,60 (1,08–2,38; p = 0,039) in high Hg ≥ 1,89

Downs and black checklist – subscales	Vigeh et al.²⁰20 Vigeh M, Yokoyama K, Ramezanzadeh F, Dahaghin M, Sakai T, Morita Y, et al. Lead and other trace metals in preeclampsia: a case-control study in Tehran, Iran. Environ Res. 2006;100(02): 268–275. Doi: 10.1016/j.envres.2005.05.005 https://doi.org/10.1016/j.envres.2005.05...	El-Badry et al.²⁵25 El-Badry A, Rezk M, El-Sayed H. Mercury-induced oxidative stress may adversely affect pregnancy outcome among dental staff: a cohort study. Int J Occup Environ Med. 2018;9(03):113–119. Doi: 10.15171/ijoem.2018.1181 https://doi.org/10.15171/ijoem.2018.1181...	Bommarito et al.²¹21 Bommarito PA, Kim SS, Meeker JD, Fry RC, Cantonwine DE, McElrath TF, et al. Urinary trace metals, maternal circulating angiogenic biomarkers, and preeclampsia: a single-contaminant and mixture-based approach. Environ Health. 2019;18(01):63. Doi: 10.1186/s12940-019-0503-5 https://doi.org/10.1186/s12940-019-0503-...	Liu et al.²²22 Liu T, Zhang M, Guallar E, Wang G, Hong X, Wang X, et al. Trace minerals, heavy metals, and preeclampsia: findings from the Boston Birth Cohort. J Am Heart Assoc. 2019;8(16):e012436. Doi: 10.1161/JAHA.119.012436 https://doi.org/10.1161/JAHA.119.012436...	Louopou et al.²³23 Louopou RC, Trottier H, Arbuckle TE, Fraser WD. Dental amalgams and risk of gestational hypertension in the MIREC study. Pregnancy Hypertens. 2020;21:84–89. Doi: 10.1016/j.preghy.2020.04.015 https://doi.org/10.1016/j.preghy.2020.04...	Wang et al.²⁴24 Wang Y,Wang K, Han T, Zhang P, Chen X,WuW, et al. Exposure to multiple metals and prevalence for preeclampsia in Taiyuan, China. Environ Int. 2020;145:106098. Doi: 10.1016/j.envint.2020.106098 https://doi.org/10.1016/j.envint.2020.10...
Reporting (10 items)	7	7	9	9	9	8
External Validity (3 items)	2	3	3	3	3	3
Internal validity – bias (7 items)	5	5	5	5	5	5
Power (1 item)	1	1	1	1	1	1
Total score	17	18	20	21	21	19

Federação Brasileira das Sociedades de Ginecologia e Obstetrícia Av. Brigadeiro Luís Antônio, 3421, sala 903 - Jardim Paulista, 01401-001 São Paulo SP - Brasil, Tel. (55 11) 5573-4919 - Rio de Janeiro - RJ - Brazil
E-mail: editorial.office@febrasgo.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] Address for correspondence Aline de Oliveira Dantas, medical student, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, 2° andar, Sala 49, 21044-020, Cidade Universitária, Rio de Janeiro, RJ, Brazil (e-mail: alinedantas27@yahoo.com.br).