Associations between maternal fish intake, maternal and cord polyunsaturated fatty acid concentrations and offspring anthropometrics at birth and at 7 and 13 years of age
Authors: McMullan James E , Yeates Alison J. , Allsopp Philip J. , Mulhern Maria S. , Strain J.J. , van Wijngaarden Edwin , Myers Gary J. , Shroff Emelyn , Shamlaye Conrad F , McSorley Emeir M. 
Published: December 2024

Findings from animal models suggest early exposure to polyunsaturated fatty acids (PUFAs) during pregnancy may influence developmental plasticity including adiposity(1). Birth cohort studies examining associations between offspring weight and maternal n-3 PUFA status or maternal fish intakes, the richest dietary source of n-3 PUFAs have been few and have yielded inconsistent findings. Some have reported lower weight at birth and throughout childhood with increasing maternal fish intakes and n-3 PUFA status(2), whilst others have observed positive or null associations(3,4). These have focused on the first few years of life and have been conducted within low fish-consuming populations. Our study provides novel data by examining associations between maternal fish consumption and prenatal PUFA (n-3 & n-6) status and offspring weight at birth and throughout childhood (7 & 13 years) in a high fish-eating population.

Pregnant women were enrolled in the Seychelles Child Development Study Nutrition Cohort 2 between 2008-2011. Serum PUFAs were quantified in maternal blood collected at 28-weeks’ gestation and in cord blood collected at delivery using gas-chromatography tandem mass spectrometry. Maternal fish consumption was assessed at 28-weeks’ gestation using a Fish Use Questionnaire. Childbirth weight (kg) was measured at delivery and classified according to WHO growth standards(5) (n = 1185). Child height (m), weight (kg), waist and hip circumference (cm) were recorded at 7 (n = 1167) and 13 (n = 878) years. Statistical analysis was conducted using logistic and multiple linear regression adjusting for child sex, gestational age, maternal age, BMI, alcohol use, socioeconomic status, and parity. Models at 7 & 13 years were additionally adjusted for child height and fish intakes.

Women were consuming on average 8.49 ± 4.51 fish meals/week during pregnancy. No significant associations were found between maternal fish intakes and anthropometric outcomes at birth, 7 & 13 years. No significant associations were observed between maternal PUFAs and offspring weight at birth. At both 7 & 13 years, however, higher maternal total n-6 PUFAs were associated with increased child weight [7yr; β = 0.070, p = 0.003, 13yr; β = 0.097, p = 0.004], waist circumference [7yr; β = 0.086, p = 0.003, 13yr; β = 0.105, p = 0.004], and hip circumference [7yr; β = 0.062, p = 0.027, 13yr; β = 0.090, p = 0.013]. No significant associations were found between cord n-6 PUFAs and birth weight. In quartile analysis, cord docosahexaenoic acid (DHA; C22:6n-3) concentrations <0.071mg/ml were associated with a higher risk of large for gestational age (LGA; >90th percentile) when compared to cord DHA concentrations >0.129mg/ml [OR 4.17, p = 0.017]. There were no significant associations between cord PUFAs and anthropometric outcomes at 7 & 13 years.

These findings suggest lower cord DHA, an n-3 PUFA, may be associated with higher risk of LGA at birth whilst higher n-6 PUFAs during pregnancy may be associated with adiposity development throughout childhood. Future work is needed to determine the potential long-term metabolic consequences of such associations.