Omega 3 fatty acids on child growth, visual acuity and neurodevelopment

Healthy pregnant women and healthy full-term infants; lactating mothers; randomized controlled trials (RCTs) and quasi-RCTs; multiple countries; outcomes included growth, visual acuity, neurodevelopment.

Pregnant women received DHA- or DHA+EPA-rich supplements (e.g., fish oil, algal oil) starting mid-pregnancy and continuing to delivery; lactating mothers received DHA/LC-PUFA supplementation during lactation; infants received DHA- and AA-containing fortified formulas (and in some trials DHA-enriched foods) starting within the first weeks after birth and continuing for several months up to 12–18 months; regimens varied by trial (different forms and doses).

Omega-3 LCPUFA supplementation during pregnancy and/or lactation did not demonstrate clear, consistent long-term benefits for growth, visual acuity, or neurodevelopment in term infants. Some trials reported transient or domain-specific improvements (e.g., early visual function or certain cognitive measures) but results were heterogeneous and not consistently replicated. Postnatal supplementation via infant formula showed little or no effect on growth; some early studies suggested improved visual acuity with DHA-supplemented formulas, but findings were not universal. Meta-analyses generally found no clinically meaningful effects on neurodevelopment or visual outcomes, and effects on birth size were small and inconsistent. Potential influences of DHA status, optimal DHA levels, and genetic factors (e.g., FADS variants) may affect outcomes; further standardized, high-quality trials are needed to define any definitive benefit.

Heterogeneous dosing/timing/outcome measures across trials; variable risk of bias and study quality; small to moderate sample sizes; short follow-up in many studies; confounding factors such as breastfeeding status; inconsistent measurement tools; results may not generalize across populations; potential genetic influences on DHA metabolism.