Metals in Pregnancy Alter Your Baby's Immune System at Birth

Babies are born with immune systems already altered by the metals their mothers were exposed to during pregnancy.

What Researchers Found in Cord Blood

A 2026 study in Environ Epigenet analyzed cord blood from 428 newborns and measured prenatal exposure to four metals: manganese, lead, arsenic, and cadmium. They looked at how these metals changed the mix of immune cells the baby was born with.

The effects depended on the baby's sex.

Girls and Boys Responded Differently

Female babies had a 4.85% increase in granulocytes (a type of white blood cell), driven mainly by arsenic exposure. Male babies saw a 3.44% decrease in granulocytes, driven by cadmium.

Male babies also showed higher proportions of CD8+ T-cells. Female babies had lower natural killer cells. The metal mixture was reprogramming the immune system in opposite directions depending on sex.

Why This Matters

Your immune cell balance at birth sets the stage for how your body fights infections and inflammation for years. Shifting that balance before a baby even takes their first breath could increase risk for allergies, autoimmune problems, and infections in childhood.

How to Reduce Metal Exposure During Pregnancy

Filter drinking water (especially for lead and arsenic). Avoid rice-based foods high in arsenic. Don't smoke (cadmium source). And switch to non-toxic baby products to keep the chemical load low from day one.

Also see glass food storage for safer alternatives.

Source: Kupsco et al. (2026). Environ Epigenet.