Discovery: Food packaging, shampoo, clothes, and other household products contain chemicals that may make it harder for some women to get pregnant, suggests the first study on the subject.

It's still too early to recommend that women who want to conceive try to avoid these products, said lead researcher Chunyuan Fei, a Ph.D. student in epidemiology at the University of California, Los Angeles. But her results are concerning enough to warrant further work.

"This is quite a new topic and lots of things are unknown," Fei said. "Because these chemicals are widespread, I think it's important to conduct more study."

The chemicals Fei and colleagues looked at belong to a group called perfluorinated chemicals, or PFCs, which appear in a variety of common products, from upholstery to pesticides. In particular, the researchers focused on perfluorooctane sulfonate and perfluorooctanoate, which are respectively called PFOS and PFOA.

Studies have linked PFOS and PFOA to toxic effects in the livers, immune systems, and reproductive systems of animals. In people, Fei and colleagues previously found that women with many children had lower blood levels of PFOS and PFOA than did women with fewer children.

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