Influence of seafood and vitamin supplementation on maternal and umbilical cord blood mercury concentration.

BACKGROUND: The purpose of this study was to examine the influence of maternal seafood consumption and vitamin supplementation during pregnancy on maternal and umbilical cord blood mercury (Hg) concentration.

METHODS: In this study of 145 healthy pregnant women (mean age 28.1±5.2 years), we administered questionnaires, collected paired maternal/umbilical cord blood samples, and measured the anthropometrics of newborns. Blood Hg concentration was assayed by inductively coupled plasma-mass spectrometry.

RESULTS: Sixty-one of these women (42.1%) used vitamins >3 times/wk prenatally. Seventy-eight of our study participants (61.9%) reported eating higher amounts of seafood during pregnancy. We found a strong correlation (r=0.76, p<0.001) between Hg levels in the paired maternal/umbilical cord blood samples. Mothers with high seafood consumption had a 2.91-fold greater risk (adjusted odds ratio 2.91, 95% confidence interval: 1.04-8.15, p=0.042) of high Hg levels (>5.8 μg/L). However, mothers whose prenatal vitamin intake was >3 times/wk were found to have low Hg levels (≤5.8 μg/L) (adjusted odds ratio 0.06, 95% confidence interval: 0.01-049, p=0.008).

CONCLUSION: High seafood consumption was an independent risk factor for high maternal Hg level, while vitamin supplementation was a protective factor. Further study is needed to investigate the specific effect of vitamins on Hg level.