Can exposure to PCBs and pesticides during pregnancy affect a newborn's weight and size at birth?

What's actually in it

Persistent organic pollutants (POPs) include PCBs (from old electrical equipment and contaminated fish), organochlorine pesticides like DDE (a breakdown product of DDT), and dioxins. These chemicals were widely used decades ago, banned or restricted, but they don't break down. They build up in fat tissue and pass from mother to fetus through the placenta and breast milk.

Even people who have never worked with these chemicals carry measurable levels from contaminated food, particularly fatty fish, meat, and dairy. Pregnant people transfer some of their stored body burden to the fetus during the nine months of development.

What the research says

The 2026 ENVIRONAGE study in Environ Res measured POP levels in pregnant women and then tracked their newborns' size and weight at birth. Higher prenatal POP exposure was linked to lower birth weight and shorter body length, particularly in girls.

The sex-specific findings are important: female newborns showed stronger associations with growth restriction than male newborns at the same exposure levels. This suggests POPs interact with sex hormones during fetal development in a way that affects girls and boys differently.

The main exposure routes during pregnancy are fatty animal products: farmed salmon, high-fat dairy, meat fat, and shellfish from contaminated waters. Organic produce matters less for POPs than for pesticides, but choosing lower-fat fish varieties (sardines, mackerel) and diversifying protein sources can reduce exposure.