Moderate Freshwater Fish Intake, but Not n-3 Polyunsaturated Fatty Acids, Is Associated with a Reduced Risk of Small for Gestational Age in a Prospective Cohort of Chinese Pregnant Women

Abstract

Background: Although previous studies have found that maternal fish intake is associated with fetal growth, the role of freshwater fish intake remains unknown.

Objective: Our aim was to examine the relationships of freshwater fish and n-3 polyunsaturated fatty acids (PUFAs) intake with the risk of small for gestational age (SGA) in Chinese pregnant women.

Design: This was a prospective analysis of data from the Tongji Birth cohort in Wuhan, China, from 2018 to 2021.

Participants/settings: This study included 1,701 pregnant women who had completed a food frequency questionnaire dietary assessment during mid-pregnancy.

Main outcome measures: Intake of fish was assessed by a semi-quantitative food frequency questionnaire. Total intake of n-3 PUFAs was the sum of data collected from both dietary and supplemental sources of n-3 PUFAs. Birth information was extracted from medical records.

Statistical analyses: Multivariate logistic regression models were applied to estimate odds ratios and 95% CIs.

Results: The median (interquartile range) intake of freshwater fish and total n-3 PUFAs was 12.1 (4.3 to 26.4) g/d and 68.2 (24.5 to 370.0) mg/d, respectively. Moderate intake of freshwater fish was associated with reduced risk of SGA. Compared with the lowest quintile (0-3.2 g/d), the multivariable-adjusted odds ratio for women in the fourth quintile of freshwater fish intake (17.9 to 30.0 g/d) was 0.50 (95% CI 0.25 to 0.96). We found a nonlinear association between freshwater fish intake and SGA risk (P_nonlinearity = .027). However, maternal n-3 PUFAs intake was not significantly associated with SGA risk, either from total intake or from dietary sources alone.

Conclusions: Moderate freshwater fish intake during pregnancy is associated with lower risk of SGA in a Chinese population. This finding provides supportive evidence for freshwater fish intake during pregnancy, particularly for the inland areas of developing countries.

Keywords: Fish intake; Freshwater fish intake; Pregnancy; Small for gestational age; n-3 polyunsaturated fatty acids.