Document Type
Journal Article
Publication Date
3-1-2016
Journal
Environmental Health Perspectives
Volume
124
Issue
3
Inclusive Pages
373-379
DOI
10.1289/ehp.1408596
Abstract
BACKGROUND: Methylmercury (MeHg) may affect fetal growth; however, prior research often lacked assessment of mercury speciation, confounders, and interactions.
OBJECTIVE: Our objective was to assess the relationship between MeHg and fetal growth as well as the potential for confounding or interaction of this relationship from speciated mercury, fatty acids, selenium, and sex.
METHODS: This cross-sectional study includes 271 singletons born in Baltimore, Maryland, 2004-2005. Umbilical cord blood was analyzed for speciated mercury, serum omega-3 highly unsaturated fatty acids (n-3 HUFAs), and selenium. Multivariable linear regression models controlled for gestational age, birth weight, maternal age, parity, prepregnancy body mass index, smoking, hypertension, diabetes, selenium, n-3 HUFAs, and inorganic mercury (IHg).
RESULTS: Geometric mean cord blood MeHg was 0.94 μg/L (95% CI: 0.84, 1.07). In adjusted models for ponderal index, βln(MeHg) = -0.045 (g/cm3) × 100 (95% CI: -0.084, -0.005). There was no evidence of a MeHg × sex interaction with ponderal index. Contrastingly, there was evidence of a MeHg × n-3 HUFAs interaction with birth length [among low n-3 HUFAs, βln(MeHg) = 0.40 cm, 95% CI: -0.02, 0.81; among high n-3 HUFAs, βln(MeHg) = -0.15, 95% CI: -0.54, 0.25; p-interaction = 0.048] and head circumference [among low n-3 HUFAs, βln(MeHg) = 0.01 cm, 95% CI: -0.27, 0.29; among high n-3 HUFAs, βln(MeHg) = -0.37, 95% CI: -0.63, -0.10; p-interaction = 0.042]. The association of MeHg with birth weight and ponderal index was affected by n-3 HUFAs, selenium, and IHg. For birth weight, βln(MeHg) without these variables was -16.8 g (95% CI: -75.0, 41.3) versus -29.7 (95% CI: -93.9, 34.6) with all covariates. Corresponding values for ponderal index were -0.030 (g/cm3) × 100 (95% CI: -0.065, 0.005) and -0.045 (95% CI: -0.084, -0005).
CONCLUSION: We observed an association of increased MeHg with decreased ponderal index. There is evidence for interaction between MeHg and n-3 HUFAs; infants with higher MeHg and n-3 HUFAs had lower birth length and head circumference. These results should be verified with additional studies.
CITATION: Wells EM, Herbstman JB, Lin YH, Jarrett J, Verdon CP, Ward C, Caldwell KL, Hibbeln JR, Witter FR, Halden RU, Goldman LR. 2016. Cord blood methylmercury and fetal growth outcomes in Baltimore newborns: potential confounding and effect modification by omega-3 fatty acids, selenium, and sex. Environ Health Perspect 124:373-379; http://dx.doi.org/10.1289/ehp.1408596.
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APA Citation
Wells, E., Herbstman, J., Lin, Y., Jarrett, J., Verdon, C., Ward, C., Caldwell, K., Hibbeln, J., Witter, F., Halden, R., & Goldman, L. R. (2016). Cord blood methylmercury and fetal growth outcomes in Baltimore newborns: Potential confounding and effect modification by omega-3 fatty acids, selenium, and sex. Environmental Health Perspectives, 124 (3). http://dx.doi.org/10.1289/ehp.1408596
Peer Reviewed
1
Open Access
1
Comments
Publication of EHP lies in the public domain and is therefore without copyright. All text from EHP may be reprinted freely.
Reproduced with permission of Environmental Health Perspectives.