For the first time, researchers have counted the number of chemicals found in the blood of pregnant women. Of 163 chemicals studied, 43 were found in virtually all of the 268 women in the study.
Many of the chemicals, including cancer-causing BPA and PCBs, are being used in cookware, furniture, processed foods and beauty products.
Other chemicals have been banned for decades, raising concern about negative effects in children.
The study is published in the journal Environmental Health Perspectives.