Low Consumption of Seafood in Early Pregnancy as a Risk Factor for Preterm Delivery: Prospective Cohort Study

Abstract

Persons living in the Faroe Islands eat a lot of and reportedly have high birth weights and long pregnancies. Eating seafood rich in long-chain n-3 fatty acids possibly prolongs gestation or promotes fetal growth. There is evidence from randomized trials that fish can delay spontaneous delivery and also prevent recurrent preterm delivery. The present prospective cohort study of 8729 pregnant Danish women sought to determine whether a low intake of seafood early in pregnancy disposes to preterm delivery, low birth weight, or less fetal growth. Participants completed a questionnaire about their intake in gestational weeks 16 and 30. Only live-born singleton infants lacking malformations were included, and women taking oil supplements were excluded. In Denmark, eating as part of a hot meal, in a sandwich, or cold in a salad is a strong independent predictor of erythrocytic n-3 fatty acids. Low birth weight, preterm birth, and intrauterine growth restriction all tended to be less frequent as consumption increased. There also were increases in mean birth weight, duration of gestation, and birth weight adjusted for gestational age. The associations, especially those for preterm birth and mean length of gestation, were most evident at the lower end of the range of exposure. After adjusting for potential confounding factors, the association between intake and the risk of fetal growth restriction persisted but was less strong. Relatively low consumption was a strong risk factor for preterm delivery and low birth weight in this prospective study. These outcomes might be minimized by providing small amounts of n-3 fatty acids-in the form of itself or oil-to women reporting low or no intake of fish.