Marine n-3 Long-Chain Polyunsaturated Fatty Acid Intake in Pregnancy and Risk of Early Life Infections in 3 Nordic...

n-3 (ω-3) long-chain polyunsaturated fatty acids (n-3 LCPUFAs) have anti-inflammatory effects that may influence immune-mediated diseases.

We investigated whether higher maternal pregnancy intake of n-3 LCPUFA is associated with a lower incidence of infections in young children.

We used data from 3 Nordic cohorts: the Norwegian Mother, Father and Child Cohort study (MoBa, n = 76,026), the Finnish Diabetes Prediction and Prevention Study (DIPP, n = 560), and the Copenhagen Prospective Studies on Asthma in Childhood 2010 cohort (COPSAC₂₀₁₀, n = 680). Childhood infections up to age 36 mo were assessed using questionnaires in MoBa, coxsackievirus B 1-6 (CVB1-6) neutralizing antibodies in DIPP, and pathogenic viral PCR identification from acute respiratory episodes in COPSAC₂₀₁₀. Maternal n-3 LCPUFA intake was assessed through validated food frequency questionnaires in MoBa and DIPP, whereas COPSAC₂₀₁₀ used a randomized trial design where pregnant women received fish oil capsules or a placebo.

Higher n-3 LCPUFA intake was not significantly associated with lower respiratory tract infection (adjusted incidence rate ratio [aIRR]: 0.99; 95% CI: 0.94-1.03) but was associated with a reduced risk of upper respiratory tract infections (aIRR: 0.99; 95% CI: 0.98-0.99) and gastroenteritis (aIRR: 0.96; 95% CI: 0.95-0.98) per g/d up to age 36 mo in MoBa. The DIPP study found no association between n-3 LCPUFA intake and having ≥1 CVB infection (adjusted odds ratio: 1.74; 95% CI: 0.64-4.72, per g/d). The COPSAC₂₀₁₀ trial found no significant effects of the intervention for pathogen-specific respiratory episodes (IRR: 0.86; 95% CI: 0.69-1.07).

This study does not provide consistent evidence that higher maternal n-3 LCPUFA pregnancy intake reduces the risk of infections in early childhood.

This trial was registered as NCT00798226, https://clinicaltrials.gov/study/NCT00798226.