Demographic and health characteristics associated with fish and n-3 fatty acid supplement intake during pregnancy: results from pregnancy cohorts in the ECHO programme

Objective: n-3 fatty acid consumption during pregnancy is recommended for optimal pregnancy outcomes and offspring health. We examined characteristics associated with self-reported fish or n-3 supplement intake. Design: Pooled pregnancy cohort studies. Setting: Cohorts participating in the Environmental influences on Child Health Outcomes (ECHO) consortium with births from 1999 to 2020. Participants: A total of 10 800 pregnant women in twenty-three cohorts with food frequency data on fish consumption; 12 646 from thirty-five cohorts with information on supplement use. Results: Overall, 246 % reported consuming fish never or less than once per month, 401 % less than once a week, 221 % 1-2 times per week and 132 % more than twice per week. The relative risk (RR) of ever (v. never) consuming fish was higher in participants who were older (114, 95 % CI 110, 118 for 35-40 v. <29 years), were other than non-Hispanic White (113, 95 % CI 108, 118 for non-Hispanic Black; 105, 95 % CI 101, 110 for non-Hispanic Asian; 106, 95 % CI 102, 110 for Hispanic) or used tobacco (104, 95 % CI 101, 108). The RR was lower in those with overweight v. healthy weight (097, 95 % CI 095, 10). Only 162 % reported n-3 supplement use, which was more common among individuals with a higher age and education, a lower BMI, and fish consumption (RR 15, 95 % CI 123, 182 for twice-weekly v. never). Conclusions: One-quarter of participants in this large nationwide dataset rarely or never consumed fish during pregnancy, and n-3 supplement use was uncommon, even among those who did not consume fish.