Chemicals found in food packaging, waterproof clothing, upholstery and carpets could be damaging women's fertility.
A study published in the journal Human Reproduction measured levels of perfluorinated chemicals (PFCs) in the blood of 1,240 women.
Those with higher levels were more likely to take longer to become pregnant.
PFCs are useful because they are resistant to heat, have the ability to repel water and oil and are commonly used in non-stick pans. However, high concentrations have been linked to organ damage in animals, and the chemicals have the ability to remain for long periods in the body.
UK experts said more research was needed to confirm any link.
The researchers, from the University of California, analysed blood samples taken at the woman's first antenatal visit, then interviewed the women about how long it had taken them to get pregnant. They found that the likelihood of infertility - taking more than a year or IVF to get pregnant, was significantly higher for women with higher levels of PFCs in their bloodstream.
One of the researchers Dr Chunyuan Fei said that earlier studies had suggested that PFCs might impair the growth of babies in the womb. She also said that more women in the groups with higher exposure to PFCs had problems with irregular menstrual cycles , which might suggest that interference with hormones was the reason.
Professor Jorn Olsen, who led the study, said that the team were now waiting for further studies to confirm the link between fertility problems and PFCs.
Tony Rutherford, chairman of the British Fertility Society, said that the findings were "interesting". "It is an important finding and certainly warrants further detailed research, particularly in those trying for a family.... The study emphasises the importance of remaining vigilant to potential environmental factors that may impact on fertility."
January 2009 | 
Non-Stick Pans Might Harm Fertility
