Impact of dietary mercury intake during pregnancy on the health of neonates and children: a systematic review

Abstract

Context Growing evidence suggests that prenatal exposure to methyl mercury through the maternal diet could have great influence on the neurological and physical development of neonates and young children. Objective The aim of this review was to evaluate the clinical repercussions of maternal exposure to methyl mercury during pregnancy on the health of fetuses, neonates, and children up to 8 years of age. Data Sources The Web of Science, PubMed, CINAHL, Scopus, and Dialnet Plus databases were searched for articles published in English or Spanish from 1990 to 2020. Study Selection Original articles published in English or Spanish from 1990 to 2020 were eligible for inclusion. All study designs were eligible. Animal studies were excluded. Two authors independently screened studies for inclusion. From the 971 records initially identified, 19 studies were included in the systematic review. Data Extraction PRISMA guidelines were followed. Outcomes extracted included maternal dietary exposure to methyl mercury during pregnancy, possible health repercussions in offspring up to 8 years of age, and quantitative measurement of mercury in a biological sample. All studies met the requirements established for assessing both study quality and risk of bias. Results Prenatal exposure to mercury was consistently associated with lower birth weight, but only one study reported a negative association with length at birth. Higher mercury levels were also related to lower scores in various neuropsychological and developmental tests. Conclusion The literature shows clear evidence of the adverse effects of maternal methyl mercury exposure on anthropometric variables and cognitive or physical development in children. It is noteworthy, however, that mercury toxicity may sometimes be mitigated by other essential nutrients in the maternal diet, such as polyunsaturated fatty acids.

Prenatal Mercury Exposure and Neurodevelopment up to the Age of 5 Years: A Systematic Review

“…Our findings do not replicate those of a systematic review of maternal dietary mercury intake which included 15 studies of neurodevelopmental outcomes in children up to 8 years old [ 87 ]. The review concluded there was clear evidence that maternal dietary exposure adversely affected childhood cognitive development, although this may be mitigated by nutrients in mercury-containing foods such as fish.…”

Endocrine Disrupting Chemicals’ Effects in Children: What We Know and What We Need to Learn?

“…Hg is a known endocrine disruptor that is able to lower progesterone levels, increase estrogen, and adversely affect the steroid synthesis pathway [ 107 ]. Prenatal exposure to Hg was consistently associated with lower BW [ 110 ].…”

Occupational and environmental mercury exposure and human reproductive health - a review

“…The data are evidence of a clear negative effect of maternal MeHg exposure on anthropometric variables, cognitive or physical growth in children. Furthermore, mercury poisoning might sometimes be lessened by vital nutrients present in the maternal diet ( 66 ). A recent report indicated that moderate fish consumption, consistent with current health recommendations during pregnancy, was related to improvement in the metabolic health of offspring, while higher maternal mercury exposure was related with an unfavorable metabolic profile in children ( 67 ).…”