Can chromium exposure during pregnancy affect how your baby grows?

What's actually in it

Chromium exists in two forms. Chromium(III) is an essential trace mineral found in supplements, broccoli, and whole grains. Chromium(VI) is the toxic industrial form that contaminates drinking water near manufacturing sites. Both forms can reach the fetus during pregnancy.

Many prenatal vitamins contain chromium(III) as a supplement, and some dietary sources provide more than people realize. The line between a helpful dose and a harmful one is thinner than you might think.

What the research says

A 2026 study in Environ Res examined how chromium exposure during pregnancy affected fetal growth, and whether the effects differed between baby boys and baby girls.

Higher maternal chromium levels were associated with reduced birth weight and smaller head circumference in some groups. But the effects weren't the same for both sexes. Male fetuses appeared more sensitive to chromium at certain exposure levels, showing greater growth restriction than female fetuses at the same dose.

The study measured chromium through maternal blood and urine samples taken during pregnancy. Even at levels considered "normal" for the general population, there were measurable effects on fetal growth parameters.

This doesn't mean you should avoid chromium entirely. Your body needs it in small amounts. But be cautious with chromium supplements during pregnancy, especially high-dose ones. Stick to prenatal vitamins with standard amounts, and if your tap water comes from an area with industrial activity, consider a water filter that removes heavy metals.