Effects of smoking and marine diet on birthweight in Greenland.

: The associations of maternal smoking and blood mercury concentration on birthweight were studied in 1106 liveborn singletons from Greenland with a gestational period of 37+ weeks. After control for population group, smoking was significantly associated with low birthweight while consumption of marine mammals, maternal or cord blood mercury concentration were not. Only in West Greenlanders a week association was found between mercury and low birthweight. The Greenlandic diet of marine mammals has high concentrations of mercury and organochlorines which may reduce birthweight, and it is rich in n-3 fatty acids which have been shown to prolong pregnancy and thereby increase birthweight. In the present study neither previous reports of a negative influence of marine diet on birthweight due to methylmercury or previous reports of a positive influence of marine diet on birthweight due to n-3 fatty acids were supported.