Blood mercury levels and fish consumption in pregnancy: Risks and benefits for birth outcomes in a prospective observational birth cohort

Abstract

BackgroundTo avoid exposure to mercury, government advice on fish consumption during pregnancy includes information on fish species to avoid and to limit, while encouraging consumption of least two portions of fish per week. Some women may, however, chose to avoid fish completely during pregnancy despite potential benefits to the fetus.ObjectivesOur aims were to evaluate the effects of blood mercury levels in pregnant women on birth outcomes in the UK, and to compare outcomes in those who ate fish with those who did not.MethodsPregnant women were enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). Whole blood samples for singleton pregnancies with a live birth were analysed for Hg by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4044). Fish intake was determined by a food frequency questionnaire during pregnancy. Data collected on the infants included anthropometric variables and gestational age at delivery. Regression models were adjusted for covariates using SPSS v23.ResultsThere were no significant associations of maternal blood Hg level with birthweight, head circumference or crown–heel length in adjusted linear regression models. Similarly, there were no increased odds of low birthweight or preterm delivery in adjusted logistic regression models. When the models were repeated after stratification into fish-eaters and there were no associations except for a negative association with birthweight in non-fish-eaters (unstandardised B coefficient −58.4 (95% confidence interval −113.8, −3.0) g, p = 0.039).ConclusionModerate mercury levels in pregnancy were not associated with anthropometric variables, or on the odds of low birthweight or preterm birth. Fish consumption may have a protective effect on birthweight. Consumption of fish in line with government guidelines during pregnancy should be encouraged.

Spatial Mapping Applied to Low Birth Weight Incidence , Indonesia

“…This finding supports a relationship between exposure to MeHg and birth weight [van Wijngaarden et al, 2014]. There were evidences for associations of B-Hg with increases in birth weight [Taylor et al, 2016]. LBW was more likely to happen among women who reside within 8 kilometers with fish consumption [Burch et al, 2014].…”

“…These factors also contribute to the role of maternal place of residence as a mediator of maternal stress and adverse reproductive outcomes among women [Miranda et al, 2009]. One study found evidence of the associations between B-Hg with birth weight increases [Taylor et al, 2016]. Mothers who lived in the highlands were at risk for hypoxic fetus that caused neonatal asphyxia.…”

Mercury exposure and its effects on fertility and pregnancy outcome

“…The role of Hg as a toxicant in sexual reproduction and pregnancy is quite neglected compared with the great attention spent on reports regarding neurotoxicology from this heavy metal. Despite some contradictory evidence, the role of Hg in human reproduction is going to be a major alarming issue . This MiniReview is aimed at analysing the published documentation about the effects of organic and inorganic Hg in human fertility, the outcome of childbirth, congenital abnormalities, loss of pregnancy and menstrual disorders.…”

Environmental Chemicals and Preterm Birth: Biological Mechanisms and the State of the Science

“…A study by Taylor and colleagues conducted in the UK found weak evidence of a protective effect of blood mercury levels measured in the mother early in pregnancy (median 11 weeks) and PTB, but this association attenuated in adjusted models (100). In a study population of women who were predominantly African American or of Caribbean decent, investigators found a protective effect of higher mercury levels in maternal urine during the last trimester of pregnancy, but the estimate was imprecise (101).…”