Supplementation with long chain polyunsaturated fatty acids (LCPUFA) to breastfeeding mothers for improving child growth and development.

Systematic review and meta-analysis of eight randomized trials including 1567 participants from high-income countries. The review enrolled healthy pregnant and/or lactating women who breastfed or intended to breastfeed and their term infants, and assessed child neurodevelopment, visual acuity, growth, allergy, and maternal mood outcomes.

Breastfeeding or pregnant-and-lactating mothers received oral long-chain polyunsaturated fatty acid supplements, mainly DHA-rich fish oil, algal oil, cod liver oil, or DHA capsules, during pregnancy and/or lactation. Regimens ranged from 200 mg DHA/day to 1.1 g DHA plus 1.6 g EPA, with other trials using 10 mL cod liver oil/day or 4.5 g fish oil/day containing 1.5 g n-3 LCPUFA; comparators were placebo or control oils.

Overall, LCPUFA supplementation to breastfeeding mothers did not improve children's neurodevelopment, visual acuity, or growth, and the evidence is inconclusive for routine use. Pooled language outcomes were null or borderline, including beyond 24 months (SMD -0.27, 95% CI -0.56 to 0.02), and intelligence or problem-solving beyond 24 months was also null (SMD 0.00, 95% CI -0.36 to 0.36). One study found better child attention at more than 24 months (MD 4.70, 95% CI 1.30 to 8.10; n=110), but this was weak evidence and did not alter the overall conclusion. Growth findings were inconsistent and mostly small, with no clear long-term difference in child weight (MD 0.13, 95% CI -0.49 to 0.74).

The evidence base was small and heterogeneous, with varying supplement types, doses, timing, and outcome measures across trials. Many pooled analyses included few studies and wide confidence intervals, long-term follow-up was limited, and some findings came from single studies. Safety and maternal outcome reporting was inconsistent, which limits confidence in firm practice recommendations.