London: A US study has suggested that pregnant women who drink from plastic bottles could be increasing their unborn child's chances of developing cancer later in life.

Researchers at the University of Illinois, who conducted their study on mice, showed how exposure to Bisphenol A (BPA), a chemical commonly found in plastic water bottles and soup cans, in the womb could increase prostate cancer risk.

According to lead researcher Gail Prins, “This is the first direct evidence that exposure to BPA during development, at levels we see in our day-to-day environment, increases the risk for prostate cancer in human prostate tissue".

"Studies of expectant mothers in the US showed that more than 95 per cent of them had BPA in their urine, which means they recently ingested these compounds."

The animal study involved implanting human prostate stem cells into mice.For the study, doses of BPA at relative levels similar to those seen in pregnant women were fed to the mice for the first two weeks after the transplant. Next, the mice were exposed to raised estrogen levels, mimicking the normal rise in estrogen seen in ageing men.

Signs of cancer developed in the prostate tissue implants in a third of the mice fed BPA, compared with just 12 per cent of mice not exposed to the chemical. But 45 per cent showed signs of cancer if the stem cells were exposed to BPA before implantation and again during development.

The research was presented at the annual meeting of the Endocrine Society in San Francisco.