“It is important to identify modifiable causes of preterm delivery and fetal growth retardation, which are strong predictors of infants’ later health and survival,” remark the authors of this study in the British Medical Journal. The study, which evaluated the link between seafood intake and preterm birth, originated because of the greater-than-normal birth weights, longer gestation periods, and higher fish consumption common to Denmark’s remote Faroe Islands.

Fish oil has been linked to delayed delivery in other studies, yet the amount of omega-3 fatty acids necessary to significantly reduce the odds for preterm birth and low birth weights is unknown. In this study, 8,729 pregnant women in Aarhus, Denmark, completed seafood intake questionnaires in the 16th and 30th weeks of pregnancy.

Seafood consumption included fish and shellfish and was divided into four intake categories: never, 0-1 times monthly, 1-3 times monthly, or once or more per week.

Results: Women who consumed no fish were 3.6 times more likely to have a preterm delivery than women consuming fish at least weekly. Incidence of preterm delivery fell progressively from 7.1% in the zero-consumption group to 1.9% in the at-least-weekly consumption group.

Only fish served as a “hot meal” or “open sandwich” was considered in the final results, to limit variables. The authors determined that beyond an average of 15 grams of fish per day, or 0.15g of omega-3 fatty acids, no further effects were derived from seafood consumption, regarding preterm-birth prevention.