London - A chemical found in everyday plastic items could lead to a sixfold increase in the risk of a premature baby.
Scientists said bisphenol A – used in containers, water bottles, food cans and till receipts – can affect women who come into contact with it before they even conceive.
The substance has already been linked to premature birth in mothers-to-be who are exposed to it.
Researchers led by the Harvard TH Chan School of Public Health in Boston, US, analysed the urine of 364 women at a fertility clinic before they became pregnant, of whom 32 gave birth to premature babies.
Phthalates, another chemical found in food packaging, doubled the risk of an early birth in women who had high levels before conceiving, they added.
Jennifer Yland, who led the study, said: "Exposure to these chemicals is widespread as they are found in food packaging, consumer products, medical devices, plastic bottles and receipts."
It is thought the two substances can cause chemical changes as women’s eggs develop that can lead to premature birth. They have also been linked to asthma and infertility, the meeting in Denver was told.
Bisphenol A, used since the 1960s, mimics the female hormone oestrogen and has been linked to breast and prostate cancer.