Fish consumption, omega-3 fatty acid intake, and pregnancy outcomes
Recent studies have reported protective associations between maternal seafood consumption and preterm birth and inconsistent results for associations between maternal seafood consumption and small for gestational age (SGA) infants. Protective effects are hypothesized to be due to the long chain omega-3 fatty acids present in seafood. ^ We used data from control participants in the National Birth Defects Prevention Study (NBDPS) to assess associations between consumption of fish and two pregnancy outcomes, preterm birth and SGA, using logistic regression. NBDPS did not collect information on shellfish consumption or types of fish eaten, therefore, we used data from the National Health and Nutrition Examination Survey (NHANES) to develop a linear regression model to estimate omega-3 intake among non-pregnant US women of child bearing age based on servings of fish and sociodemographic characteristics. This model was then used to estimate omega-3 intake for NBDPS participants and logistic regression was used to assess associations between the estimates of omega-3 intake and each pregnancy outcome. ^ No statistically significant associations were found between fish consumption and preterm birth among control participants in the NBDPS. Adjusted odds ratio (aOR) estimates ranged from 0.73 to 0.88 among women in the three highest categories of fish consumption compared to women who ate no fish. Women who consumed fish daily had increased odds of having an SGA infant (aOR 2.02, 95% CI 1.22-3.35). Estimates of omega-3 intake were highly correlated with reported fish consumption (r=0.95) and the association estimates between omega-3 intake and preterm birth were of similar magnitude to those for fish consumption. For SGA, the association estimate for the highest omega-3 intake category versus no omega-3 intake from fish was attenuated compared to the elevated risk observed among women with the highest fish intake. ^ While we did not find a statistically significant association between fish consumption and preterm birth, our point estimates were similar in magnitude to recent studies that have shown a modest protective effect. Previous studies have reported an elevated risk of delivering an SGA infant among high consumers of specific seafood types. Our results suggest that pregnant women who consume extremely high amounts of fish have an increased risk of delivering an SGA infant and future studies should confirm this finding and investigate whether it is due to seafood contaminants.^
Benjamin, Renata Hughes, "Fish consumption, omega-3 fatty acid intake, and pregnancy outcomes" (2016). Texas Medical Center Dissertations (via ProQuest). AAI10127410.