Nanoplastics During Pregnancy Affect Baby's Brain

Polystyrene nanoplastics from plastic packaging and food containers cross the placenta. A 2026 study in Scientific Reports found that even low doses during pregnancy affected postnatal development in mice, including lower brain weight and kidney weight at 42 days, along with disrupted developmental milestones.

What the Research Found

Researchers in Brazil exposed pregnant mice to polystyrene nanoplastics. The offspring were evaluated for developmental milestones from birth through 21 days. Male offspring were then euthanized at days 42 and 70 to assess organ development and sperm quality.

In the nanoplastic-exposed group: female offspring showed increased anogenital distance (a marker of hormonal disruption). Males showed a tendency toward reduced anogenital distance and delayed cliff-avoidance reflex, an early neurological development test. At day 42, males had significantly lower brain and kidney weights.

The researchers note these are preliminary findings with a small sample, but they match a growing pattern in the literature: nanoplastic exposure during pregnancy consistently shows up in offspring development outcomes.

Where Polystyrene Comes From

Polystyrene is used in single-use cups, to-go containers, foam packaging, and some food storage containers. When heated, scratched, or exposed to acidic foods, it breaks down and releases nanoscale particles. These particles are small enough to cross biological barriers, including the placenta.

Replace polystyrene and plastic food containers with glass, stainless steel, or borosilicate glass. These don't break down into nanoparticles. Browse non-toxic baby products free of plastic, and non-toxic kitchen alternatives for pregnancy-safe food storage.

Source: Valencise L, Lozano AFQ, de Barros JWF, Cyr DG, De Grava Kempinas W (2026). Sci Rep.