Associations of prenatal mercury exposure from maternal fish consumption and polyunsaturated fatty acids with child neurodevelopment: a prospective cohort study in Italy.
BACKGROUND
Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy.


METHODS
A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders.


RESULTS
Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months.


CONCLUSIONS
In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found.
Institute of Hygiene and Clinical Epidemiology, University Hospital of Udine, Udine, Italy. francesca.valent@uniud.it
Francesca
F
Valent
Marika
M
Mariuz
Maura
M
Bin
D'Anna
D
Little
Darja
D
Mazej
Veronica
V
Tognin
Janja
J
Tratnik
Alison J
AJ
McAfee
Maria S
MS
Mulhern
Maria
M
Parpinel
Marco
M
Carrozzi
Milena
M
Horvat
Giorgio
G
Tamburlini
Fabio
F
Barbone
D000328:Adult; D000818:Animals; D002657:Child Development / Q000187:drug effects*; D004034:Diet Surveys; D005231:Fatty Acids, Unsaturated / Q000097:blood; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006801:Humans; D007223:Infant; D007558:Italy; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D008628:Mercury / Q000032:analysis / Q000633:toxicity*; D009420:Nervous System / Q000187:drug effects* / Q000254:growth & development; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011446:Prospective Studies
D005231:Fatty Acids, Unsaturated; D008628:Mercury