When pregnant moms take omega-3 supplements, their babies have less oxidative stress at birth—but this benefit doesn’t last, and by age 12, it’s gone, especially if the mom has allergies.

We analyzed the available evidence and found that when pregnant women take omega-3 supplements, their babies show lower levels of oxidative stress at birth. Oxidative stress is a type of cellular damage that can happen when there’s an imbalance between harmful molecules and the body’s ability to neutralize them. This benefit, however, does not appear to last. By age 12, the difference in oxidative stress levels between babies whose mothers took omega-3s and those who didn’t is no longer detectable, especially if the mother has allergies [1]. The evidence we’ve reviewed so far includes 55 assertions that support this pattern, with none that contradict it. This suggests a consistent trend: omega-3 supplementation during pregnancy may help reduce oxidative stress in newborns, but the effect seems temporary. The absence of lasting benefit by age 12 indicates that the body’s natural processes, environmental factors, or other influences likely override the early protective effect. The mention of maternal allergies adds a layer of complexity — it suggests that the mother’s own health may influence how long, or if, the benefit persists. We don’t know why the effect fades, or whether factors like diet, activity, or genetics after birth play a role. There’s also no data on whether the temporary reduction in oxidative stress leads to any measurable health changes later in childhood. What this means for families: If you’re pregnant and considering omega-3 supplements, the evidence suggests a short-term benefit for your baby at birth, but don’t expect it to protect them from cellular stress years later. It’s one small factor among many that shape long-term health.