Maternal fish consumption, mercury levels, and risk of preterm delivery.
BACKGROUND
Pregnant women receive mixed messages about fish consumption in pregnancy because unsaturated fatty acids and protein in fish are thought to be beneficial, but contaminants such as methylmercury may pose a hazard.


METHODS
In the Pregnancy Outcomes and Community Health (POUCH) study, women were enrolled in the 15th to 27th week of pregnancy from 52 prenatal clinics in five Michigan communities. At enrollment, information was gathered on amount and category of fish consumed during the current pregnancy, and a hair sample was obtained. A segment of hair closest to the scalp, approximating exposure during pregnancy, was assessed for total mercury levels (70-90% methylmercury) in 1,024 POUCH cohort women.


RESULTS
Mercury levels ranged from 0.01 to 2.50 pg/g (mean = 0.29 microg/g; median = 0.23 microg/g). Total fish consumption and consumption of canned fish, bought fish, and sport-caught fish were positively associated with mercury levels in hair. The greatest fish source for mercury exposure appeared to be canned fish. Compared with women delivering at term, women who delivered before 35 weeks' gestation were more likely to have hair mercury levels at or above the 90th percentile (> or = 0.55 microg/g), even after adjusting for maternal characteristics and fish consumption (adjusted odds ratio = 3.0; 95% confidence interval, 1.3-6.7).


CONCLUSIONS
This is the first large, community-based study to examine risk of very preterm birth in relation to mercury levels among women with low to moderate exposure. Additional studies are needed to see whether these findings will be replicated in other settings.
Xue
Fei
F
Harvard School of Public Health, Harvard University, Boston, Massachusetts, USA.
Holzman
Claudia
C
Rahbar
Mohammad Hossein
MH
Trosko
Kay
K
Fischer
Lawrence
L
D000818:Animals; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D005399:Fishes; D005506:Food Contamination; D005519:Food Preservation; D006197:Hair / Q000737:chemistry; D006801:Humans; D018811:Maternal Exposure; D008628:Mercury / Q000032:analysis*; D008824:Michigan / Q000453:epidemiology; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D014874:Water Pollutants, Chemical / Q000032:analysis
D014874:Water Pollutants, Chemical; D008628:Mercury